Polymer recyclate processes and products

ABSTRACT

Methods for processing LLDPE recyclates including, but not limited to, polyethylene and polypropylene and compositions therefrom are provided. LLDPE recyclate can be visbroken to improve processing characteristics and/or devolatilized to remove waste byproducts to produce processed LLDPE recyclates. Processed LLDPE recyclates are compounded with pre-consumer polyolefins to produce blend compositions having acceptable or even improved processing characteristics. Such pre-consumer polyolefins can also be visbroken to further tailor processing characteristics of such polymer blends. A combination of extruders and/or extruder zones can be used at the same or different locations for visbreaking and/or compounding of both LLDPE recyclate and/or pre-consumer polyolefins.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is filed under the Patent Cooperation Treaty, whichclaims the priority of U.S. Provisional Patent Application Ser. No.63/213,429, entitled “POLYMER RECYCLATE PROCESSES AND PRODUCTS,” filedon Jun. 22, 2021, and U.S. Provisional Patent Application Ser. No.63/238,655, entitled “POLYMER RECYCLATE PROCESSES AND PRODUCTS,” filedon Aug. 30, 2021, the contents of which are incorporated by referenceherein in their entirety.

FIELD OF THE INVENTION

The present disclosure relates to the use of extrusion processes toimprove the processing characteristics of polyolefin recyclates, eitheralone or in combination with other polyolefins. The invention furtherrelates to compositions produced by such processes.

BACKGROUND OF THE INVENTION

Polyolefins, including polyethylene and polypropylene, may be used inmany applications, including packaging for food and other goods,electronics, automotive components, and a variety of manufacturedarticles. Waste plastic materials may be obtained from a variety ofsources, including differential recovery of municipal plastic wastesthat are constituted of flexible packaging (cast film, blown film andBOPP film), rigid packaging, blow molded bottles and injection moldedcontainers. Often, through a step of separation from other polymers,such as PVC, PET or PS, two main polyolefinic fractions may be obtained,namely polyethylenes (including, HDPE, LDPE, LLDPE) and polypropylenes(including homopolymers, random copolymers, heterophasic copolymers).

The multicomponent nature of the recycled polyolefins or thepolyolefinic fractions may result in low mechanical and opticalperformances of prepared articles or of polyolefin formulations in whichpart of a virgin LLDPE is replaced by recycled polymer. Unpredictablemechanical and/or optical properties can result from variability of oneor more characteristics of the recycled polyolefin including, but notlimited to, melt index, high load melt index, melt elasticity, complexviscosity, or combinations thereof. In addition, the recycledpolyolefins or the polyolefinic fractions may contain impurities orcontamination by other components. Moreover, the molecular weight, themolecular weight distribution and/or the comonomer content of therecycled polyolefins or of the polyolefinic fractions can limit therange of virgin LLDPEs into which recycled polyolefins can beincorporated. Another limitation for the use of recycled polyolefins maybe the presence of unpleasant odors coming from volatile organiccompounds which may have been absorbed in these polymers during theirusage.

In the case of polyethylenes, it may be desirable to separatepolyethylene waste into portions which are predominately HDPE,predominately MDPE, predominately LDPE, predominately LLDPE, orpredominately polypropylene. This disclosure provides—in the case of theLLDPE portion—processes to produce polyolefin compositions comprisingrecycled LLDPE, such polyolefin compositions having a useful combinationof properties. Such disclosed processes may be highly flexible and couldbe implemented with commonly used equipment and familiar techniques toproduce a wide variety of products.

SUMMARY OF THE INVENTION

In general, the present disclosure relates to methods for processingpolyolefin recyclates, in particular linear low density polyethylene(“LLDPE”) recyclates. Such processing includes implementing in anextruder visbreaking conditions to convert a LLDPE recyclate into avisbroken LLDPE recyclate having a reduced weight average molecularweight. In some embodiments, the LLDPE recyclate is also subjected todevolatilization conditions to convert the LLDPE recyclate into avisbroken LLDPE recyclate having a reduced weight average molecularweight and a reduced volatile organic compounds (“VOC”) content.

Visbreaking conditions include thermal visbreaking and/or peroxidationvisbreaking. Thermal visbreaking includes temperature, pressure, andmechanical shear sufficient to cause polymer chain scission topredominate over polymer chain branching or crosslinking. Peroxidationvisbreaking may occur when a peroxide as added to the polymer melt in anextruder followed by thermal decomposition of the peroxide to form freeradicals, which react with the polymer chain to result in chainscission. In some embodiments, visbreaking conditions consist of thermalvisbreaking at a temperature at least 180° C. above the melting point ofthe LLDPE in the absence of or substantially in the absence of oxygen.

Devolatilization conditions can include reduction of VOC in a polyolefinby a portion of an extruder having an intensive mixing arrangement anddevolatilization sections to enable removal of VOC at high temperatures.Devolatilization conditions can be further enhanced by injection of agas into the extruder, distribution of the gas in the polymer melt toscavenge VOC components, and extraction of the gas and scavenged VOCcomponents by venting and/or vacuum.

In some embodiments, the processed LLDPE recyclate can be pelletized asa product at the extruder discharge. In other embodiments, the processedLLDPE recyclate can be fed to a second extruder to be compounded orblended with a virgin LLDPE. In yet other embodiments, the virgin LLDPEcan be the polyolefin powder product from a polymerization apparatus, apelletized polyolefin, or the polyolefin melt, which is the product of athird extruder. In any of the embodiments in this paragraph, the virginLLDPE can have been subjected to a visbreaking process prior to additionto the second reactor.

In some embodiments, virgin LLDPE is fed to a third extruder and thepolymer melt form the third extruder is co-fed to the second extruderalong with processed LLDPE recyclate melt.

In some embodiments, a composition is provided where the composition isor comprises a polymer blend of from 5 wt. % to 90 wt. % of a LLDPErecyclate and from 10 wt. % to 95 wt. % of a virgin LLDPE, wherein allweight percentages are based on the combined weight of the polymer blendand one or both of the LLDPE recyclate feedstock and the virgin LLDPEare visbroken. Visbreaking can be thermal visbreaking and/orperoxidation visbreaking.

The foregoing has outlined rather broadly the features and technicaladvantages of the present invention in order that the detaileddescription of the invention that follows may be better understood.Additional features and advantages of the invention will be describedhereinafter, which form the subject matter of the claims of theinvention. It should be appreciated by those skilled in the art that theconception and specific embodiments disclosed may be readily utilized asa basis for modifying or designing other film structures and/orprocesses for carrying out the same purposes of the present invention.It should also be realized by those skilled in the art that suchequivalent constructions do not depart from the spirit and scope of theinvention as set forth in the appended claims. The novel features whichare believed to be characteristic of the invention, both as to itsstructure and method of manufacture, together with further objects andadvantages will be better understood from the following description.

BRIEF DESCRIPTION OF THE FIGURES

The claimed subject matter may be understood by reference to thefollowing description taken in conjunction with the accompanyingdrawings, in which like reference numerals identify like elements, andin which:

FIG. 1 is a simplified flow diagram of the process to obtain a processedLLDPE recyclate according to embodiments of the invention;

FIG. 2 is simplified flow diagram of the process to obtain a blend of aprocessed LLDPE recyclate and a virgin LLDPE using two extrudersaccording to embodiments of the invention;

FIG. 3 is simplified flow diagram of the process to obtain a blend of aprocessed LLDPE recyclate and a virgin LLDPE using three extrudersaccording to embodiments of the invention;

FIG. 4 is an overlaid graph showing the effects of visbreaking an LLDPEon complex viscosity according to embodiments of the invention; and

FIG. 5 is an overlaid graph showing the effects of visbreaking an LLDPEon molecular weight according to embodiments of the invention.

While the disclosed process and composition are susceptible to variousmodifications and alternative forms, the drawings illustrate specificembodiments herein described in detail by way of example. It should beunderstood, however, that the description herein of specific embodimentsis not intended to limit the invention to the particular formsdisclosed, but on the contrary, the intention is to cover allmodifications, equivalents, and alternatives falling within the spiritand scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

Illustrative embodiments of the subject matter claimed below will now bedisclosed. In the interest of clarity, some features of some actualimplementations may not be described in this specification. It will beappreciated that in the development of any such actual embodiments,numerous implementation-specific decisions must be made to achieve thedeveloper's specific goals, such as compliance with system-related andbusiness-related constraints, which will vary from one implementation toanother. Moreover, it will be appreciated that such a developmenteffort, even if complex and time-consuming, would be a routineundertaking for those of ordinary skill in the art having the benefit ofthis disclosure.

The words and phrases used herein should be understood and interpretedto have a meaning consistent with the understanding of those words andphrases by those skilled in the relevant art. No special definition of aterm or phrase, i.e., a definition that is different from the ordinaryand customary meaning as understood by those skilled in the art, isintended to be implied by consistent usage of the term or phrase herein.To the extent that a term or phrase is intended to have a specialmeaning, i.e., a meaning other than the broadest meaning understood byskilled artisans, such a special or clarifying definition will beexpressly set forth in the specification in a definitional manner thatprovides the special or clarifying definition for the term or phrase. Itmust also be noted that, as used in the specification and the appendedclaims, the singular forms “a,” “an,” and “the” include pluralreferences unless otherwise specified.

For example, the following discussion contains a non-exhaustive list ofdefinitions of several specific terms used in this disclosure (otherterms may be defined or clarified in a definitional manner elsewhereherein). These definitions are intended to clarify the meanings of theterms used herein. It is believed that the terms are used in a mannerconsistent with their ordinary meaning, but the definitions arenonetheless specified here for clarity.

Definitions

“Antioxidant agents,” as used herein, means compounds that inhibitoxidation, a chemical reaction that can produce free radicals and chainreactions.

“Compounding conditions,” as used herein, means temperature, pressure,and shear force conditions implemented in an extruder to provideintimate mixing of two or more polymers and optionally additives toproduce a substantially homogeneous polymer product.

“Devolatilization conditions,” as used herein, means subjecting apolymer melt in an extruder to injection and withdrawal of a scavenginggas, addition of heat, physical mixing, pressure reduction by venting orapplying vacuum, or a combination thereof. Devolatilization conditionsimplemented in an extruder are sufficient to reduce the VOC of a polymerfed to the extruder by a predetermined percentage and/or to apredetermined VOC target for polymer exiting the extruder.Devolatilization conditions are directed to reduction of VOC in apolyolefin by a portion of an extruder having an intensive mixingarrangement and devolatilization sections to enable removal of VOC athigh temperatures. Devolatilization conditions can be further enhancedby injection of a gas into the extruder, distribution of the gas in thepolymer melt to scavenge VOC components, and extraction of the gas andscavenged VOC components by venting or vacuum.

“Devolatilized LLDPE recyclate,” as used herein, means the productobtained by subjecting an LLDPE recyclate feedstock to devolatilizationconditions as described herein.

“Extruder,” as used herein within the context of the “first extruder,”second extruder,” and “third extruder,” in some embodiments, meansseparate extrusion apparatuses, and in other embodiments, means separatesections within a single extrusion apparatus. In some embodiments, thefirst extruder and the second extruder are separate machines. In someembodiments, the first extruder and the second extruder are separatesections in a single machine. In some embodiments, the second extruderand the third extruder are separate machines. In some embodiments, thesecond extruder and the third extruder are separate sections in a singlemachine. In some embodiments, the first extruder, the second extruder,and the third extruder are separate machines. In some embodiments, thefirst extruder, the second extruder, and the third extruder are separatesections in a single machine. “Extruder,” as used herein includes anydevice or combinations of devices capable of continuously processing oneor more polyolefins under visbreaking conditions, compoundingconditions, melting conditions, or devolatilization conditions,including, but not limited to, Farrel continuous mixers (FCM™ mixers,available from Farrel Corporation, Ansonia, Conn.).

“HDPE,” as used herein, means ethylene homopolymers and ethylenecopolymers produced in a suspension, solution, slurry, or gas phasepolymerization process and having a density in the range of 0.940 g/cm³to 0.970 g/cm³.

“LLDPE recyclate feedstock,” as used herein, means LLDPE recyclate aftercollection and sorting but prior to being subjected to the processesdisclosed herein.

“LLDPE recyclate,” as used herein, means post-consumer recycled (“PCR”)LLDPE and/or post-industrial recycled (“PIR”) LLDPE. Polyolefinrecyclate is derived from an end product that has completed its lifecycle as a consumer item and would otherwise be disposed of as waste(e.g., a polyethylene water bottle) or from plastic scrap that isgenerated as waste from an industrial process. Post-consumer polyolefinsinclude polyolefins that have been collected in commercial andresidential recycling programs, including flexible packaging (cast film,blown film and BOPP film), rigid packaging, blow molded bottles, andinjection molded containers. Usually, through a step of separation fromother polymers, such as PVC, PET or PS, two main polyolefinic fractionsare obtained, namely polyethylene recyclate (including HDPE, MDPE, LDPE,and LLDPE) and polypropylene recyclate (including homopolymers, randomcopolymers, and heterophasic copolymers). Polyethylene recyclate can befurther separated to recover a portion having LLDPE as the primaryconstituent. In addition to contamination from dissimilar polymers,LLDPE recyclate frequently contains other impurities such as PMMA, PC,wood, paper, textile, cellulose, food, and other organic wastes, many ofwhich cause the LLDPE recyclate to have an unpleasant odor before andafter typical processing.

“LDPE,” as used herein, means ethylene homopolymers and ethylenecopolymers produced in a high pressure free radical polymerization andhaving a density in the range of 0.910 g/cm³ to 0.940 g/cm³.

“LLDPE,” as used herein, means ethylene copolymers produced in asuspension, solution, slurry, or gas phase polymerization process andhaving a density in the range of 0.910 g/cm³ to 0.940 g/cm³.

“MDPE,” as used herein, means ethylene copolymers produced in asuspension, solution, slurry, or gas phase polymerization process andhaving a density in the range of 0.925 g/cm³ to 0.940 g/cm³.

“Melting conditions,” as used herein, means temperature, pressure, andshear force conditions, either alone or in combination with one another,that are required to produce a polymer melt from a feed of polymerpellets or powder.

“Processed LLDPE recyclate,” as used herein, means the product obtainedby subjecting an LLDPE recyclate feedstock to visbreaking conditions orto visbreaking conditions followed by devolatilization conditions, asdescribed herein.

“Virgin LLDPEs,” as used herein, are pre-consumer polyolefins.Pre-consumer polyolefins are polyolefin products obtained directly orindirectly from petrochemical feedstocks fed to a polymerizationapparatus. Pre-consumer polyolefins can be subjected to postpolymerization processes such as, but not limited to, extrusion,pelletization, visbreaking, and/or other processing completed before theproduct reaches the end-use consumer. In some embodiments, virgin LLDPEshave a single heat history. In some embodiments, virgin LLDPEs have morethan one heat history. In some embodiments, virgin LLDPEs comprise noadditives. In some embodiments, virgin LLDPEs comprise additives.

“Visbreaking conditions,” as used herein, means thermal visbreakingand/or peroxidation visbreaking. Thermal visbreaking includestemperature, pressure, and/or mechanical shear sufficient to causepolymer chain scission to predominate of polymer chain branching orcrosslinking. Peroxidation visbreaking occurs when a peroxide as addedto the polymer melt in an extruder followed by thermal decomposition ofthe peroxide to form free radicals, which react with the polymer chainto result in chain scission. As used herein, a polymer that has beenvisbroken will have lower number average and weight average molecularweight, a narrower molecular weight distribution, higher melt index, anda higher high load melt index. In some embodiments, visbreakingconditions consist of thermal visbreaking at a temperature greater thanor equal to 300° C., or in the range of from 320° C. to 400° C., in theabsence of or substantially in the absence of oxygen.

“Visbreaking,” as used herein, means treating a polymer thermally and/orchemically to produce a reduction in M_(n), M_(w), and MWD(M_(w)/M_(n)), and an increase in melt index I₂ (ASTM D-1238, 2.16kg@190° C.) and high load melt index I₂₁ (ASTM D-1238, 21.6 kg@190° C.)of the LLDPE so treated. Applying high temperatures and/or addingradical source such as peroxides to polyolefinic materials results indegradation of the polymer chains and reduction of the average molecularweight of the polymer. In parallel, the molecular weight distributiongets narrower. When intentionally performing such methods for modifyingthe properties of polymers, these practices are commonly called“visbreaking”.

“Visbroken LLDPE recyclate,” as used herein, means the product obtainedby subjecting an LLDPE recyclate feedstock to visbreaking conditions asdescribed herein.

Processing LLDPE Recyclate Feedstock

In FIG. 1 , flow diagram 100 includes a visbreaking extruder 110 havinga visbreaking zone 115 and an optional devolatilization zone 120. LLDPErecyclate feedstock 125 is added to visbreaking extruder 110 proximateto the inlet end of the extruder. The LLDPE recyclate is drawn throughthe extruder 110 by one or more rotating screw drives in the barrel ofthe visbreaking extruder 110. The length of the visbreaking extruder 110is separated into one or more zones. Each zone can have one or more of aspecified thread pitch on the screw drive, inlets for injection of gas130, 135, vents or vacuum connections for withdrawal of gas 140, meansfor addition or withdrawal of heat, inlets for injection of peroxide145, and inlets for injection of additives in order to impartpreselected process conditions including, but not limited to pressure,temperature, and/or shear force.

FIG. 1 shows an embodiment with both a visbreaking zone 115 and anoptional devolatilization zone 120. Other embodiments can have avisbreaking zone 115 alone without a devolatilization zone. Processconditions in the visbreaking extruder 110 can further be controlled byrotation speed of the screw drive. Processed LLDPE recyclate 150 iswithdrawn proximate to the discharge of the visbreaking extruder 110 forfurther processing or pelletization.

LLDPE Recyclate Feedstock

In some embodiments, LLDPE recyclate feedstock is derived from ethylenehomopolymers, copolymers of units derived from ethylene and unitsderived from one or more of C₃-C₁₂ α-olefins, copolymers of unitsderived from ethylene and units derived from one or more of alphamono-olefins. Such C₃-C₁₂ α-olefins include, but are not limited to,substituted or unsubstituted C₃ to C₁₂ alpha olefins such as propylene,butene, pentene, hexene, heptene, octene, nonene, decene, undecene,dodecane, and isomers thereof. When present, comonomers can be presentin amounts up to 20 wt %, 15 wt %, 10 wt %, or 5 wt %. LLDPE recyclatefeedstock can be derived as a portion of post-consumer recycledpolyolefin and/or post-industrial recycled polyolefin that ispredominately comprised of LLDPE recyclate, wherein “predominately”means greater than or equal to 80 wt %, greater than or equal to 85 wt%, greater than or equal to 90 wt %, or greater than or equal to 95 wt%, based on the total weight of the LLDPE recyclate feedstock.

Such ethylene homopolymers and/or copolymers can be produced in asuspension, solution, slurry, or gas phase process, using knownequipment and reaction conditions. In some embodiments, polymerizationtemperatures range from about 0° C. to about 300° C. at atmospheric,subatmospheric, or superatmospheric pressures.

Slurry or solution polymerization systems can utilize subatmospheric orsuperatmospheric pressures and temperatures in the range of about 40° C.to about 300° C. An exemplary liquid phase polymerization system isdescribed in U.S. Pat. No. 3,324,095, the disclosure of which is fullyincorporated by reference herein. Liquid phase polymerization systemsgenerally comprise a reactor to which olefin monomer and catalystcomposition are added, and which contains a liquid reaction medium fordissolving or suspending the polyolefin. The liquid reaction medium mayconsist of the bulk liquid monomer or an inert liquid hydrocarbon thatis nonreactive under the polymerization conditions employed. Althoughsuch an inert liquid hydrocarbon need not function as a solvent for thecatalyst composition or the polymer obtained by the process, it usuallyserves as solvent for the monomers employed in the polymerization. Amongthe inert liquid hydrocarbons suitable for this purpose are isopentane,hexane, cyclohexane, heptane, benzene, toluene, and the like. Reactivecontact between the olefin monomer and the catalyst composition shouldbe maintained by constant stirring or agitation. The reaction mediumcontaining the olefin polymer product and unreacted olefin monomer iswithdrawn from the reactor continuously. The olefin polymer product isseparated, and the unreacted olefin monomer and liquid reaction mediumare recycled into the reactor.

Gas phase polymerization systems can utilize superatmospheric pressuresin the range of from 1 psig (6.9 kPag) to 1,000 psig (6.9 MPag), 50 psig(344 kPag) to 400 psig (2.8 MPag), or 100 psig (689 kPag) to 300 psig(2.1 MPag), and temperatures in the range of from 30° C. to 130° C. or65° C. to 110° C. Gas phase polymerization systems can be stirred orfluidized bed systems. In some embodiments, a gas phase, fluidized bedprocess is conducted by passing a stream containing one or more olefinmonomers continuously through a fluidized bed reactor under reactionconditions and in the presence of catalyst composition at a velocitysufficient to maintain a bed of solid particles in a suspendedcondition. A stream containing unreacted monomer is withdrawn from thereactor continuously, compressed, cooled, optionally partially or fullycondensed, and recycled into the reactor. Product is withdrawn from thereactor and make-up monomer is added to the recycle stream. As desiredfor temperature control of the polymerization system, any gas inert tothe catalyst composition and reactants may also be present in the gasstream.

In some embodiments, a Ziegler-Natta (ZN)catalyst is used. Suchcatalysts are based on a Group IVB transition metal compound and anorganoaluminum compound (co-catalyst). Such transition metals, include,but not limited to, Ti, Zr, and Hf Nonlimiting examples of ZN catalystsystems include TiCl₄+Et₃Al and TiCl₃+AlEt₂Cl. Such LLDPE homopolymersand/or copolymers have some long-chain branching and a density in therange of from 0.910 g/cm³ to 0.940 g/cm³.

LLDPE recyclate feedstock, derived from LLDPE as described above, can becharacterized by having:

-   -   i) a density in the range of from 0.910 g/cm³ to 0.940 g/cm³ or        from 0.915 g/cm³ to 0.935 g/cm³;    -   ii) a melt index (2.16 kg, 190° C.) less than or equal to less        than or equal to 5.0 g/10 min.;    -   iii) a molecular weight distribution (M_(w)/M_(n)) greater than        or equal to 5.0, greater than or equal to 7.0, greater than or        equal to 10.0, or greater than or equal to 15.0;    -   iv) a weight average molecular weight (“M_(w1)”) greater than or        equal to 85,000 daltons, greater than or equal to 120,000        daltons, greater than or equal to 180,000 daltons, or greater        than or equal to 200,000 daltons, and/or less than or equal to        500,000 daltons, less than or equal to 400,000 daltons, less        than or equal to 350,000 daltons, or less than or equal to        250,000 daltons; and    -   v) a melt elasticity (“ER”) greater than or equal to 0.5.

In some embodiments, in addition to the foregoing properties, the LLDPErecyclate feedstock can be further characterized by having one or moreof

-   -   vi) a first VOC content;    -   vii) a first high load melt index (I₂₁, 21.6 kg, 190° C.;    -   viii) a first melt index ratio (MIR, I₂₁/I₂);    -   ix) a first long chain branching parameter (g′) in the range of        from 0.85 to 1.00, from 0.90 to 0.99, or from 0.92 to 0.98;    -   x) a first overall polydispersity ratio (PDR);    -   xi) a first complex viscosity ratio (η*_(0.1)/η*₁₀₀), wherein        η*_(0.1) is the complex viscosity at 0.1 rad/sec and η*₁₀₀ is        the complex viscosity at 100 rad/sec, both at a temperature of        190° C.; and    -   xii) a first intrinsic viscosity.

Visbreaking Extruder

LLDPE recyclate feedstock is fed to a first extruder and is subjected tovisbreaking conditions and optionally devolatilization conditions.

—Visbreaking

Visbreaking conditions are implemented in the visbreaking zone of thefirst extruder and are tailored for LLDPE. In some embodiments,visbreaking conditions means thermal visbreaking and/or peroxidationvisbreaking. In some embodiments, visbreaking conditions consist ofthermal visbreaking, wherein the temperature in the visbreaking zone isgreater than or equal to 300° C., where it is believed that chainscission reactions exceed long-chain branching and/or crosslinkingreactions. In some embodiments, temperatures in the visbreaking zone canbe in the range of from 320° C. to 500° C., from 340° C. to 480° C., orfrom 360° C. to 460° C. In some embodiments, instrumentation at thefirst extruder discharge monitors rheology directly or indirectly (I₂,I₂₁, viscosity, melt elasticity, complex viscosity ratio, or the like)to measure and assist in control of visbreaking. In some embodiments,where antioxidant addition is used in conjunction with visbreaking, theantioxidant addition point is at a location on the first extruder aftera substantial portion of the visbreaking reaction has taken place. Insome embodiments, visbreaking conditions consist of thermal visbreakingthe absence of or substantially in the absence of oxygen, whereinsubstantial absence of oxygen means less than or equal to 1.0 wt %, lessthan or equal to 0.10 wt %, or less than or equal to 0.01 wt %, based onthe total weight of polymer in the extruder. In some embodiments, thevisbreaking extruder comprises one or more melt filters.

—Devolatilization

Devolatilization conditions are optionally implemented in the firstextruder and are directed to reduction of VOC in the LLDPE recyclatefeedstock by a portion of an extruder having an intensive mixingarrangement and devolatilization sections to enable removal of VOC athigh temperatures. Devolatilization conditions can be further enhancedby: injection of a scavenging gas, such as, but not limited to,nitrogen, carbon-dioxide, water, or combinations thereof, into theextruder; distribution of the gas in the polymer melt to scavenge VOCcomponents; and extraction of the gas and scavenged VOC components byventing and/or vacuum.

Processed LLDPE Recyclate

A processed LLDPE recyclate is withdrawn from the discharge of thevisbreaking extruder, wherein “processed” means that the LLDPE recyclatefeedstock was subjected to visbreaking conditions or visbreakingconditions followed by devolatilization conditions. Processed LLDPErecyclate, as described above, can be characterized by having:

-   -   i) a density, wherein the ratio of the density of the processed        LLDPE recyclate to the density of the LLDPE recyclate feedstock        is greater than or equal to 1.0;    -   ii) a melt index (I₂), wherein the ratio of the melt index of        the processed LLDPE recyclate to the melt index of the LLDPE        recyclate feedstock is greater than or equal to 5.0, and/or the        processed LLDPE recyclate has a melt index (I2) greater than or        equal to 5.0 g/10 min.;    -   iii) a molecular weight distribution, wherein the ratio of        molecular weight distribution of the processed LLDPE recyclate        to the molecular weight distribution of the LLDPE recyclate        feedstock is less than or equal to 0.8, and/or the molecular        weight distribution of the processed LLDPE recyclate is less        than or equal to 5.0;    -   iv) a weight average molecular weight (“M_(w2)”), wherein the        ratio of the weight average molecular weight of the processed        LLDPE recyclate to the weight average molecular weight of the        LLDPE recyclate feedstock is less than or equal to 0.90 or less        than or equal to 0.80; and    -   v) a melt elasticity (“ER”), wherein the ratio of the ER of the        processed LLDPE recyclate to the ER of the LLDPE recyclate        feedstock is less than or equal to 0.50, less than or equal to        0.40, or less than or equal to 0.30 and/or the second melt        elasticity is less than 0.5.

In some embodiments, in addition to the foregoing properties, theprocessed LLDPE recyclate can be further characterized by having one ormore of:

-   -   vi) a VOC content, wherein the ratio of the VOC content of the        processed LLDPE recyclate to the VOC content of the LLDPE        recyclate feedstock is less than or equal to 0.9, 0.8, 0.7, 0.6,        or 0.5, each alone or in combination with a lower limit of        greater than or equal to 0.1;    -   vii) a high load melt index (I₂₁, 21.6 kg, 190° C.), wherein the        ratio of the high load melt index of the processed LLDPE        recyclate to the high load melt index of the LLDPE recyclate        feedstock is greater than or equal to 2.0, greater than or equal        to 3.0, or greater than or equal to 4.0;    -   viii) a melt index ratio (MIR, I₂₁/I₂), wherein the MIR of the        processed LLDPE recyclate to the MIR of the LLDPE recyclate        feedstock is less than or equal to 0.90, less than or equal to        0.85, or less than or equal to 0.80;    -   ix) a long chain branching parameter (g′), wherein the ratio of        the g′ of the processed LLDPE recyclate to the g′ of the LLDPE        recyclate feedstock is less than or equal to 1.0;    -   x) a first long chain branching index (“LCBI”) greater than or        equal to 0, and the processed LLDPE recyclate has a LCBI greater        than 0;    -   xi) an overall polydispersity ratio (PDR), wherein the ratio of        the PDR of the processed LLDPE recyclate to the PDR of the LLDPE        recyclate feedstock is less than or equal to 0.90, less than or        equal to 0.80, or less than or equal to 0.70;    -   xii) a complex viscosity ratio (η*_(0.1)/η*₁₀₀), wherein the        ratio of the complex viscosity ratio of the processed LLDPE        recyclate to the complex viscosity ratio of the LLDPE recyclate        feedstock is less than or equal to 0.7, less than or equal to        0.6, or less than or equal to 0.5, and/or the complex viscosity        ratio of the processed LLDPE recyclate is less than or equal to        3.0 or less than or equal to 2.0, and η*_(0.1) is the complex        viscosity at 0.1 rad/sec and η*₁₀₀ is the complex viscosity at        100 rad/sec, both at a temperature of 190° C.; and    -   xiii) an intrinsic viscosity [η], wherein the ratio of the        intrinsic viscosity of the processed LLDPE recyclate to the        intrinsic viscosity of the LLDPE recyclate feedstock is less        than or equal to 0.90, less than or equal to 0.80, or less than        or equal to 0.70.

Blending of Processed LLDPE Recyclate and and a Polyolefin BlendComponent-Two Extruders

In FIG. 2 , flow diagram 200 includes a visbreaking extruder 210 and acompounding extruder 255. Embodiments of the present invention as shownin FIG. 2 include a visbreaking extruder 210 having a visbreaking zone215 and a devolatilization zone 220. LLDPE recyclate feedstock 225 isadded to visbreaking extruder 210 proximate to the inlet end of theextruder. The LLDPE recyclate feedstock 225 is drawn through thevisbreaking extruder 210 by one or more rotating screw drives in thebarrel of the visbreaking extruder 210. The length of the visbreakingextruder 210 is separated into one or more zones. Each zone can have oneor more of a specified thread pitch on the screw drive, inlets forinjection of gas 230, 235, vents or vacuum connections for withdrawal ofgas 240, means for addition or withdrawal of heat, inlets for injectionof peroxide 245, and inlets for injection of additives in order toimpart preselected process conditions including, but not limited topressure, temperature, and shear force.

FIG. 2 shows an embodiment with both a visbreaking zone 215 and adevolatilization zone 220. Other embodiments can have either avisbreaking zone 215 or a devolatilization zone 220 independentlywithout the other. Process conditions in the visbreaking extruder 210can further be controlled by rotation speed of the screw drive.Processed LLDPE recyclate 250 is withdrawn proximate to the discharge ofthe visbreaking extruder 210 for further processing.

Embodiments of FIG. 2 include a second extruder 255, having acompounding zone 260. Processed LLDPE recyclate 250 is added tocompounding extruder 255 as a first blend component proximate to theinlet end of the extruder along with a polyolefin blend component 252and subjected to compounding conditions. The polyolefin blend component252 comprises a virgin polyolefin, a polyolefin recyclate feedstock, aprocessed polyolefin recyclate, or a combination thereof. In someembodiments, the virgin polyolefin comprises a virgin HDPE, a virginLLDPE, a virgin HDPE, a virgin MDPE, a virgin polypropylene, or acombination thereof. In some embodiments, the polyolefin recyclatefeedstock comprises a LDPE recyclate feedstock, a LLDPE recyclatefeedstock, a HDPE recyclate feedstock, a MDPE recyclate feedstock, apolypropylene recyclate feedstock, or a combination thereof. In someembodiments, the processed polyolefin recyclate comprises a processedLDPE recyclate, a second processed LLDPE recyclate, a processed HDPErecyclate, a processed MDPE recyclate, a processed polypropylenerecyclate, or a combination thereof. In some embodiments, a polyolefinblend component comprises a virgin LLDPE, a LLDPE recyclate feedstock, aprocessed LLDPE recyclate, or a combination thereof. The mixture ofLLDPE recyclate 250 and polyolefin blend component 252 is drawn throughthe compounding extruder 255 by one or more rotating screw drives in thebarrel of the extruder 255. One or more additional inlets proximate tothe inlet end of the extruder provide for the addition of antioxidantagent 265 and/or other components 270. The length of the compoundingextruder 255 can be separated into one or more zones. Each zone can haveone or more of a specified thread pitch on the screw drive, means foraddition or withdrawal of heat, inlets for injection of additives. andvents or vacuum connections for withdrawal of gas 275, in order toimpart preselected process conditions including, but not limited topressure, temperature, and shear force. A blend 280 of the processedLLDPE recyclate 250 and the polyolefin blend component 252 is withdrawnproximate to the discharge of the compounding extruder 255 for furtherprocessing or pelletization.

In some embodiments, the polyolefin blend component can be a polyolefinpowder product from a polymerization apparatus, a pelletized polyolefin,or the polyolefin melt, which is the product withdrawn from a thirdextruder. In some of these embodiments, the polymerization apparatuscomprises two, three, or more polymerization reactors and/or two, three,or more polymerization zones within a polymerization reactor. Morespecific polymerization apparatus embodiments include, but are notlimited to, two or three gas phase fluidized-bed reactors in series, twoor three slurry phase reactors in series, and a gas phase fluidized-bedreactor in series with a multizone circulation reactor.

In some embodiments, the amount of the polyolefin blend component, whichitself can comprise two or more polymers, is determined based on thelogarithmic mixing rule, wherein blend components satisfy the followingequation:

${\log( {MFR}_{blend} )} = {\sum\limits_{i = 1}^{n}( {w_{i} \times \log( {MFR}_{i} )} )}$

wherein:

-   -   MFR is I₂, I₂₁, or other selected melt index;    -   MFR_(blend) is the target MFR of the final blend product;    -   n is the number of components in the blend; and    -   i is the i-th component of an n-component blend.

Blend Components

A first blend component is a processed LLDPE recyclate produced from avisbreaking extruder. A second blend component comprises a virginpolyolefin, a polyolefin recyclate feedstock, a processed polyolefinrecyclate, or a combination thereof. In some embodiments, the virginpolyolefin comprises a virgin LDPE, a virgin LLDPE, a virgin HDPE, avirgin polypropylene, or a combination thereof. In some embodiments, thepolyolefin recyclate feedstock comprises a LDPE recyclate feedstock, aLLDPE recyclate feedstock, a HDPE recyclate feedstock, a polypropylenerecyclate feedstock, or a combination thereof. In some embodiments, theprocessed polyolefin recyclate comprises a processed LDPE recyclate, asecond processed LLDPE recyclate, a processed HDPE recyclate, aprocessed polypropylene recyclate, or a combination thereof. In someembodiments, a polyolefin blend component comprises a virgin LLDPE, aLLDPE recyclate feedstock, a processed LLDPE recyclate, or a combinationthereof. When the processed LLDPE recyclate is blended with anotherprocessed LLDPE recyclate, the first LLDPE recyclate will have at leastone parameter that distinguishes it from the second processed LLDPErecyclate.

—Virgin LLDPE

In some embodiments, virgin LLDPE is from ethylene homopolymers,copolymers of units derived from ethylene and units derived from one ormore of C₃-C₁₂ α-olefins, copolymers of units derived from ethylene andunits derived from one or more of alpha mono-olefins. Such C₃-C₁₂α-olefins include, but are not limited to, substituted or unsubstitutedC₃ to C₁₂ alpha olefins such as propylene, butene, pentene, hexene,heptene, octene, nonene, decene, undecene, dodecane, and isomersthereof. When present, comonomers can be present in amounts up to 20 wt%, 15 wt %, 10 wt %, or 5 wt %.

Such ethylene homopolymers and/or copolymers can be produced in asuspension, solution, slurry, or gas phase process, using knownequipment and reaction conditions. In some embodiments, polymerizationtemperatures range from about 0° C. to about 300° C. at atmospheric,subatmospheric, or superatmospheric pressures.

Slurry or solution polymerization systems can utilize subatmospheric orsuperatmospheric pressures and temperatures in the range of about 40° C.to about 300° C. An exemplary liquid phase polymerization system isdescribed in U.S. Pat. No. 3,324,095, the disclosure of which is fullyincorporated by reference herein. Liquid phase polymerization systemsgenerally comprise a reactor to which olefin monomer and catalystcomposition are added, and which contains a liquid reaction medium fordissolving or suspending the polyolefin. The liquid reaction medium mayconsist of the bulk liquid monomer or an inert liquid hydrocarbon thatis nonreactive under the polymerization conditions employed. Althoughsuch an inert liquid hydrocarbon need not function as a solvent for thecatalyst composition or the polymer obtained by the process, it usuallyserves as solvent for the monomers employed in the polymerization. Amongthe inert liquid hydrocarbons suitable for this purpose are isopentane,hexane, cyclohexane, heptane, benzene, toluene, and the like. Reactivecontact between the olefin monomer and the catalyst composition shouldbe maintained by constant stirring or agitation. The reaction mediumcontaining the olefin polymer product and unreacted olefin monomer iswithdrawn from the reactor continuously. The olefin polymer product isseparated, and the unreacted olefin monomer and liquid reaction mediumare recycled into the reactor.

Gas phase polymerization systems can utilize superatmospheric pressuresin the range of from 1 psig (6.9 kPag) to 1,000 psig (6.9 MPag), 50 psig(344 kPag) to 400 psig (2.8 MPag), or 100 psig (689 kPag) to 300 psig(2.1 MPag), and temperatures in the range of from 30° C. to 130° C. or65° C. to 110° C. Gas phase polymerization systems can be stirred orfluidized bed systems. In some embodiments, a gas phase, fluidized bedprocess is conducted by passing a stream containing one or more olefinmonomers continuously through a fluidized bed reactor under reactionconditions and in the presence of catalyst composition at a velocitysufficient to maintain a bed of solid particles in a suspendedcondition. A stream containing unreacted monomer is withdrawn from thereactor continuously, compressed, cooled, optionally partially or fullycondensed, and recycled into the reactor. Product is withdrawn from thereactor and make-up monomer is added to the recycle stream. As desiredfor temperature control of the polymerization system, any gas inert tothe catalyst composition and reactants may also be present in the gasstream.

In some embodiments, a Ziegler-Natta (ZN)catalyst is used. Suchcatalysts are based on a Group IVB transition metal compound and anorganoaluminum compound (co-catalyst). Such transition metals, include,but not limited to, Ti, Zr, and Hf Nonlimiting examples of ZN catalystsystems include TiCl₄+Et₃Al and TiCl₃+AlEt₂Cl. Such LLDPE homopolymersand/or copolymers have some long-chain branching and a density in therange of from 0.910 g/cm³ to 0.940 g/cm³.

Virgin LLDPE can be characterized by having:

-   -   i) a density in the range of from 0.910 g/cm³ to 0.940 g/cm³ or        from 0.915 g/cm³ to 0.935 g/cm³;    -   ii) a melt index (2.16 kg, 190° C.) in the range of from 1.0        g/10 min. to 100 g/10 min., from 2.0 g/10 min. to 80 g/10 min.,        or from 3.0 g/10 min. to 50 g/10 min.;    -   iii) a molecular weight distribution (M_(w)/M₁) greater than 15;        and    -   iv) a weight average molecular weight less than or equal to        250,000 daltons, less than or equal to 200,000 daltons, less        than or equal to 150,000 daltons, or less than or equal to        100,000 daltons.

—LLDPE Recyclate Feedstock

In some embodiments, LLDPE recyclate feedstock is derived from ethylenehomopolymers, copolymers of units derived from ethylene and unitsderived from one or more of C₃-C₁₂ α-olefins, copolymers of unitsderived from ethylene and units derived from one or more of alphamono-olefins. Such C₃-C₁₂ α-olefins include, but are not limited to,substituted or unsubstituted C₃ to C₁₂ alpha olefins such as propylene,butene, pentene, hexene, heptene, octene, nonene, decene, undecene,dodecane, and isomers thereof. When present, comonomers can be presentin amounts up to 20 wt %, 15 wt %, 10 wt %, or 5 wt %. LLDPE recyclatefeedstock can be derived as a portion of post-consumer recycledpolyolefin and/or post-industrial recycled polyolefin that ispredominately comprised of LLDPE recyclate, wherein “predominately”means wherein “predominately” means greater than or equal to 80 wt %,greater than or equal to 85 wt %, greater than or equal to 90 wt %, orgreater than or equal to 95 wt %, based on the total weight of the LLDPErecyclate feedstock.

Such ethylene homopolymers and/or copolymers can be produced in asuspension, solution, slurry, or gas phase process, using knownequipment and reaction conditions. In some embodiments, polymerizationtemperatures range from about 0° C. to about 300° C. at atmospheric,subatmospheric, or superatmospheric pressures.

Slurry or solution polymerization systems can utilize subatmospheric orsuperatmospheric pressures and temperatures in the range of about 40° C.to about 300° C. An exemplary liquid phase polymerization system isdescribed in U.S. Pat. No. 3,324,095, the disclosure of which is fullyincorporated by reference herein. Liquid phase polymerization systemsgenerally comprise a reactor to which olefin monomer and catalystcomposition are added, and which contains a liquid reaction medium fordissolving or suspending the polyolefin. The liquid reaction medium mayconsist of the bulk liquid monomer or an inert liquid hydrocarbon thatis nonreactive under the polymerization conditions employed. Althoughsuch an inert liquid hydrocarbon need not function as a solvent for thecatalyst composition or the polymer obtained by the process, it usuallyserves as solvent for the monomers employed in the polymerization. Amongthe inert liquid hydrocarbons suitable for this purpose are isopentane,hexane, cyclohexane, heptane, benzene, toluene, and the like. Reactivecontact between the olefin monomer and the catalyst composition shouldbe maintained by constant stirring or agitation. The reaction mediumcontaining the olefin polymer product and unreacted olefin monomer iswithdrawn from the reactor continuously. The olefin polymer product isseparated, and the unreacted olefin monomer and liquid reaction mediumare recycled into the reactor.

Gas phase polymerization systems can utilize superatmospheric pressuresin the range of from 1 psig (6.9 kPag) to 1,000 psig (6.9 MPag), 50 psig(344 kPag) to 400 psig (2.8 MPag), or 100 psig (689 kPag) to 300 psig(2.1 MPag), and temperatures in the range of from 30° C. to 130° C. or65° C. to 110° C. Gas phase polymerization systems can be stirred orfluidized bed systems. In some embodiments, a gas phase, fluidized bedprocess is conducted by passing a stream containing one or more olefinmonomers continuously through a fluidized bed reactor under reactionconditions and in the presence of catalyst composition at a velocitysufficient to maintain a bed of solid particles in a suspendedcondition. A stream containing unreacted monomer is withdrawn from thereactor continuously, compressed, cooled, optionally partially or fullycondensed, and recycled into the reactor. Product is withdrawn from thereactor and make-up monomer is added to the recycle stream. As desiredfor temperature control of the polymerization system, any gas inert tothe catalyst composition and reactants may also be present in the gasstream.

In some embodiments, a Ziegler-Natta (ZN)catalyst is used. Suchcatalysts are based on a Group IVB transition metal compound and anorganoaluminum compound (co-catalyst). Such transition metals, include,but not limited to, Ti, Zr, and Hf Nonlimiting examples of ZN catalystsystems include TiCl₄+Et₃Al and TiCl₃+AlEt₂Cl. Such LLDPE homopolymersand/or copolymers have some long-chain branching and a density in therange of from 0.910 g/cm³ to 0.940 g/cm³.

LLDPE recyclate feedstock, derived from LLDPE as described above, can becharacterized by having:

-   -   i) a density in the range of from 0.910 g/cm³ to 0.940 g/cm³ or        from 0.915 g/cm³ to 0.935 g/cm³;    -   ii) a melt index (2.16 kg, 190° C.) less than or equal to less        than or equal to 5.0 g/10 min.;    -   iii) a molecular weight distribution (M_(w)/M₁) greater than or        equal to 5.0, greater than or equal to 7.0, greater than or        equal to 10.0, or greater than or equal to 15.0;    -   iv) a weight average molecular weight (“M_(w1)”) greater than or        equal to 85,000 daltons, greater than or equal to 120,000        daltons, greater than or equal to 180,000 daltons, or greater        than or equal to 200,000 daltons, and/or less than or equal to        500,000 daltons, less than or equal to 400,000 daltons, less        than or equal to 350,000 daltons, or less than or equal to        250,000 daltons; and    -   v) a melt elasticity (“ER”) greater than or equal to 0.5.

In some embodiments, in addition to the foregoing properties, the LLDPErecyclate feedstock can be further characterized by having one or moreof

-   -   vi) a first VOC content;    -   vii) a first high load melt index (I₂₁, 21.6 kg, 190° C.;    -   viii) a first melt index ratio (MIR, I₂₁/I₂);    -   ix) a first long chain branching parameter (g′) in the range of        from 0.85 to 1.00, from 0.90 to 0.99, or from 0.92 to 0.98;    -   x) a first overall polydispersity ratio (PDR);    -   xi) a first complex viscosity ratio (η*_(0.1)/η*₁₀₀), wherein        η*_(0.1) is the complex viscosity at 0.1 rad/sec and η*₁₀₀ is        the complex viscosity at 100 rad/sec, both at a temperature of        190° C.; and    -   xii) a first intrinsic viscosity.

—Processed LLDPE Recyclate

A processed LLDPE recyclate is withdrawn from the discharge of thevisbreaking extruder, wherein “processed” means that the LLDPE recyclatefeedstock was subjected to visbreaking conditions or visbreakingconditions followed by devolatilization conditions. Processed LLDPErecyclate, as described above, can be characterized by having:

-   -   i) a density, wherein the ratio of the density of the processed        LLDPE recyclate to the density of the LLDPE recyclate feedstock        is greater than or equal to 1.0;    -   ii) a melt index (I₂), wherein the ratio of the melt index of        the processed LLDPE recyclate to the melt index of the LLDPE        recyclate feedstock is greater than or equal to 5.0, and/or the        processed LLDPE recyclate has a melt index (I₂) greater than or        equal to 5.0 g/10 min.;    -   iii) a molecular weight distribution, wherein the ratio of        molecular weight distribution of the processed LLDPE recyclate        to the molecular weight distribution of the LLDPE recyclate        feedstock is less than or equal to 0.8, and/or the molecular        weight distribution of the processed LLDPE recyclate is less        than or equal to 5.0;    -   iv) a weight average molecular weight (“M_(w2)”), wherein the        ratio of the weight average molecular weight of the processed        LLDPE recyclate to the weight average molecular weight of the        LLDPE recyclate feedstock is less than or equal to 0.90 or less        than or equal to 0.80; and    -   v) a melt elasticity (“ER”), wherein the ratio of the ER of the        processed LLDPE recyclate to the ER of the LLDPE recyclate        feedstock is less than or equal to 0.50, less than or equal to        0.40, or less than or equal to 0.30 and/or the second melt        elasticity is less than 0.5.

In some embodiments, in addition to the foregoing properties, theprocessed LLDPE recyclate can be further characterized by having one ormore of:

-   -   vi) a VOC content, wherein the ratio of the VOC content of the        processed LLDPE recyclate to the VOC content of the LLDPE        recyclate feedstock is less than or equal to 0.9, 0.8, 0.7, 0.6,        or 0.5, each alone or in combination with a lower limit of        greater than or equal to 0.1;    -   vii) a high load melt index (I₂₁, 21.6 kg, 190° C.), wherein the        ratio of the high load melt index of the processed LLDPE        recyclate to the high load melt index of the LLDPE recyclate        feedstock is greater than or equal to 2.0, greater than or equal        to 3.0, or greater than or equal to 4.0;    -   viii) a melt index ratio (MIR, I₂₁/I₂), wherein the MIR of the        processed LLDPE recyclate to the MIR of the LLDPE recyclate        feedstock is less than or equal to 0.90, less than or equal to        0.85, or less than or equal to 0.80;    -   ix) a long chain branching parameter (g′), wherein the ratio of        the g′ of the processed LLDPE recyclate to the g′ of the LLDPE        recyclate feedstock is less than or equal to 1.0;    -   x) a first long chain branching index (“LCBI”) greater than or        equal to 0, and the processed LLDPE recyclate has a LCBI greater        than 0;    -   xi) an overall polydispersity ratio (PDR), wherein the ratio of        the PDR of the processed LLDPE recyclate to the PDR of the LLDPE        recyclate feedstock is less than or equal to 0.90, less than or        equal to 0.80, or less than or equal to 0.70;    -   xii) a complex viscosity ratio (η*_(0.1)/η*₁₀₀), wherein the        ratio of the complex viscosity ratio of the processed LLDPE        recyclate to the complex viscosity ratio of the LLDPE recyclate        feedstock is less than or equal to 0.7, less than or equal to        0.6, or less than or equal to 0.5, and/or the complex viscosity        ratio of the processed LLDPE recyclate is less than or equal to        3.0 or less than or equal to 2.0, and η*_(0.1) is the complex        viscosity at 0.1 rad/sec and Θ*_(0.1) is the complex viscosity        at 100 rad/sec, both at a temperature of 190° C.; and    -   xiii) an intrinsic viscosity [η], wherein the ratio of the        intrinsic viscosity of the processed LLDPE recyclate to the        intrinsic viscosity of the LLDPE recyclate feedstock is less        than or equal to 0.90, less than or equal to 0.80, or less than        or equal to 0.70.

Compounding Extruder

Processed LLDPE recyclate and a polyolefin blend component are fed to asecond extruder or mixer wherein the blend is subjected to compoundingconditions. Compounding conditions are implemented in the compoundingzone of the second extruder or mixer and are tailored for mixtures ofspecific polyolefins and optionally additives. Temperature, pressure,and shear force conditions are implemented in the second extruder ormixer sufficient to provide intimate mixing of the processed LLDPErecyclate and the virgin LLDPE and optionally additives to produce asubstantially homogeneous polymer blend of the processed LLDPE recyclateand the virgin LLDPE. In some embodiments, compounding conditionscomprise a temperature in the compounding zone of less than or equal to300° C., less than or equal to 250° C. or less than or equal to 200° C.In some embodiments, temperatures in the compounding zone can be in therange of from 125° C. to 195° C., from 130° C. to 180° C., or from 135°C. to 165° C.

Blends of Processed LLDPE Recyclate and a Polyolefin Blend Component

In some embodiments, the blend comprises from 5 wt. % to 90 wt. %, 10wt. % to 80 wt. %, 15 wt. % to 70 wt. %, 20 wt. % to 60 wt. %, or 25 wt.% to 50 wt. %, of a processed LLDPE recyclate and from 10 wt. % to 95wt. %, 20 wt. % to 90 wt. %, 30 wt. % to 85 wt. %, 40 wt. % to 80 wt. %,or 50 wt. % to 75 wt. %, of a polyolefin blend component, respectively,wherein all weight percentages are based on the combined weight of thepolymer blend. In some embodiments, the virgin LLDPE is visbroken. Suchvisbreaking of virgin LLDPE can be thermal visbreaking and/orperoxidation visbreaking. In some embodiments, such visbreakingconditions for a virgin LLDPE consist of thermal visbreaking at atemperature above the melting point of the LLDPE, greater than or equalto 300° C., or in the range of from 320° C. to 400° C., in the absenceof or substantially in the absence of oxygen.

In some embodiments, the blends of processed LLDPE recyclate and apolyolefin blend component, in combination with or independently of theblend ratios in the preceding paragraph, comprise a bimodal polymer,wherein the processed LLDPE recyclate product has a weight averagemolecular weight (“M_(w3)”), the polyolefin blend component has a weightaverage molecular weight (“M_(w4)”); and M_(w3)/M_(w4) is either lessthan or equal to 0.9, 0.8, 0.7, 0.6, or 0.5, or alternatively is greaterthan or equal to 1.1, 1.25, 1.5, 1.75, or 2.0.

Blending of Processed LLDPE Recyclate and a Polyolefin BlendComponent—Three Extruders

In FIG. 3 , flow diagram 300 includes a visbreaking extruder 310, amelting extruder 357, and a compounding extruder 355. Embodiments of thepresent invention as shown in FIG. 3 include a visbreaking extruder 310having a visbreaking zone 315 and a devolatilization zone 320. LLDPErecyclate feedstock 325 is added to visbreaking extruder 310 proximateto the inlet end of the extruder. The LLDPE recyclate feedstock 325 isdrawn through the visbreaking extruder 310 by one or more rotating screwdrives in the barrel of the visbreaking extruder 310. The length of thevisbreaking extruder 310 is separated into one or more zones. Each zonecan have one or more of a specified thread pitch on the screw drive,inlets for injection of gas 330, 335, vents or vacuum connections forwithdrawal of gas 340, means for addition or withdrawal of heat, inletsfor injection of peroxide 345, and inlets for injection of additives inorder to impart preselected process conditions including, but notlimited to pressure, temperature, and shear force.

FIG. 3 shows an embodiment with both a visbreaking zone 315 and adevolatilization zone 320. Other embodiments can have either avisbreaking zone 315 or a devolatilization zone 320 independentlywithout the other. Process conditions in the visbreaking extruder 310can further be controlled by rotation speed of the screw drive.Processed LLDPE recyclate 350 is withdrawn proximate to the discharge ofthe visbreaking extruder 310 for further processing.

Embodiments of FIG. 3 include a second extruder 355 having a compoundingzone 360 and a third extruder 357 having a melting zone 362. A thirdblend component 383 is added to melting extruder 357 proximate to theinlet end of the extruder optionally along with antioxidant agent 365and other components 370. The polyolefin blend component 352 comprises avirgin polyolefin, a polyolefin recyclate feedstock, a processedpolyolefin recyclate, or a combination thereof. In some embodiments, thevirgin polyolefin comprises a virgin LDPE, a virgin LLDPE, a virginHDPE, a virgin MDPE, a virgin polypropylene, or a combination thereof.In some embodiments, the polyolefin recyclate feedstock comprises a LDPErecyclate feedstock, a LLDPE recyclate feedstock, a HDPE recyclatefeedstock, a MDPE recyclate feedstock, a polypropylene recyclatefeedstock, or a combination thereof. In some embodiments, the processedpolyolefin recyclate comprises a processed LDPE recyclate, a secondprocessed LLDPE recyclate, a processed HDPE recyclate, a processed MDPErecyclate, a processed polypropylene recyclate, or a combinationthereof. In some embodiments, a polyolefin blend component comprises avirgin LLDPE, a LLDPE recyclate feedstock, a processed LLDPE recyclate,or a combination thereof. The mixture of third blend component 352 andoptional antioxidant 365 and/or other components 370 is drawn throughthe melting extruder 357 by one or more rotating screw drives in thebarrel of the melting extruder 357. The length of the melting extruder357 can be separated into one or more zones. Each zone can have one ormore of a specified thread pitch on the screw drive, means for additionor withdrawal of heat, inlets for injection of additives, and vents orvacuum connections for withdrawal of gas, in order to impart preselectedprocess conditions including, but not limited to, pressure, temperature,and shear force. A melt of the polyolefin blend component 352 iswithdrawn proximate to the discharge of the melting extruder 357 forfurther processing or pelletization.

Processed LLDPE recyclate 350 is added to compounding extruder 355proximate to the inlet end of the extruder along with the melt of thepolyolefin blend component 352. The mixture of processed LLDPE recyclate350 and polyolefin blend component 352 is drawn through the compoundingextruder 355 by one or more rotating screw drives in the barrel of thecompounding extruder 355 and the mixture is subjected to compoundingconditions. The length of the compounding extruder 355 can be separatedinto one or more zones. Each zone can have one or more of a specifiedthread pitch on the screw drive, means for addition or withdrawal ofheat, inlets for injection of additives, and vents and/or vacuumconnections for withdrawal of gas 375, in order to impart preselectedprocess conditions including, but not limited to pressure, temperature,and shear force. A blend 380 of the processed LLDPE recyclate 350 andthe polyolefin blend component 352 melt is withdrawn proximate to thedischarge of the compounding extruder 355 for further processing orpelletization.

In some embodiments, the polyolefin blend component can be a polyolefinpowder product from a polymerization apparatus, a pelletized polyolefin,or the polyolefin melt, which is the product withdrawn from a thirdextruder. In some of these embodiments, the polymerization apparatuscomprises two, three, or more polymerization reactors and/or two, three,or more polymerization zones within a polymerization reactor. Morespecific polymerization apparatus embodiments include, but are notlimited to, two or three gas phase fluidized-bed reactors in series, twoor three slurry phase reactors in series, and a gas phase fluidized-bedreactor in series with a multizone circulation reactor.

In some embodiments, the amount of the polyolefin blend component, whichitself can comprise two or more polymers, is determined based on thelogarithmic mixing rule, wherein blend components satisfy the followingequation:

${\log( {MFR}_{blend} )} = {\sum\limits_{i = 1}^{n}( {w_{i} \times \log( {MFR}_{i} )} )}$

wherein:

-   -   MFR is I₂, I₂₁, or other selected melt index;    -   MFR_(blend) is the target MFR of the final blend product;    -   n is the number of components in the blend; and    -   i is the i-th component of an n-component blend.

Blend Components

A first blend component is a processed LLDPE recyclate produced from atfrom a visbreaking extruder. A second blend component comprises a virginpolyolefin, a polyolefin recyclate feedstock, a processed polyolefinrecyclate, or a combination thereof. In some embodiments, the virginpolyolefin comprises a virgin LDPE, a virgin LLDPE, a virgin HDPE, avirgin MDPE, a virgin polypropylene, or a combination thereof. In someembodiments, the polyolefin recyclate feedstock comprises a LDPErecyclate feedstock, a LLDPE recyclate feedstock, a HDPE recyclatefeedstock, a MDPE recyclate feedstock, a polypropylene recyclatefeedstock, or a combination thereof. In some embodiments, the processedpolyolefin recyclate comprises a processed LDPE recyclate, a secondprocessed LLDPE recyclate, a processed HDPE recyclate, a processed MDPErecyclate, a processed polypropylene recyclate, or a combinationthereof. In some embodiments, the second blend component comprises avirgin LLDPE, a LLDPE recyclate feedstock, a processed LLDPE recyclate,or a combination thereof. When the processed LLDPE recyclate is blendedwith another processed LLDPE recyclate, the first LLDPE recyclate willhave at least one parameter that distinguishes it from the secondprocessed LLDPE recyclate.

—Virgin LLDPE

In some embodiments, virgin LLDPE is from ethylene homopolymers,copolymers of units derived from ethylene and units derived from one ormore of C₃-C₁₂ α-olefins, copolymers of units derived from ethylene andunits derived from one or more of alpha mono-olefins. Such C₃-C₁₂α-olefins include, but are not limited to, substituted or unsubstitutedC₃ to C₁₂ alpha olefins such as propylene, butene, pentene, hexene,heptene, octene, nonene, decene, undecene, dodecane, and isomersthereof. When present, comonomers can be present in amounts up to 20 wt%, 15 wt %, 10 wt %, or 5 wt %.

Such ethylene homopolymers and/or copolymers can be produced in asuspension, solution, slurry, or gas phase process, using knownequipment and reaction conditions. In some embodiments, polymerizationtemperatures range from about 0° C. to about 300° C. at atmospheric,subatmospheric, or superatmospheric pressures.

Slurry or solution polymerization systems can utilize subatmospheric orsuperatmospheric pressures and temperatures in the range of about 40° C.to about 300° C. An exemplary liquid phase polymerization system isdescribed in U.S. Pat. No. 3,324,095, the disclosure of which is fullyincorporated by reference herein. Liquid phase polymerization systemsgenerally comprise a reactor to which olefin monomer and catalystcomposition are added, and which contains a liquid reaction medium fordissolving or suspending the polyolefin. The liquid reaction medium mayconsist of the bulk liquid monomer or an inert liquid hydrocarbon thatis nonreactive under the polymerization conditions employed. Althoughsuch an inert liquid hydrocarbon need not function as a solvent for thecatalyst composition or the polymer obtained by the process, it usuallyserves as solvent for the monomers employed in the polymerization. Amongthe inert liquid hydrocarbons suitable for this purpose are isopentane,hexane, cyclohexane, heptane, benzene, toluene, and the like. Reactivecontact between the olefin monomer and the catalyst composition shouldbe maintained by constant stirring or agitation. The reaction mediumcontaining the olefin polymer product and unreacted olefin monomer iswithdrawn from the reactor continuously. The olefin polymer product isseparated, and the unreacted olefin monomer and liquid reaction mediumare recycled into the reactor.

Gas phase polymerization systems can utilize superatmospheric pressuresin the range of from 1 psig (6.9 kPag) to 1,000 psig (6.9 MPag), 50 psig(344 kPag) to 400 psig (2.8 MPag), or 100 psig (689 kPag) to 300 psig(2.1 MPag), and temperatures in the range of from 30° C. to 130° C. or65° C. to 110° C. Gas phase polymerization systems can be stirred orfluidized bed systems. In some embodiments, a gas phase, fluidized bedprocess is conducted by passing a stream containing one or more olefinmonomers continuously through a fluidized bed reactor under reactionconditions and in the presence of catalyst composition at a velocitysufficient to maintain a bed of solid particles in a suspendedcondition. A stream containing unreacted monomer is withdrawn from thereactor continuously, compressed, cooled, optionally partially or fullycondensed, and recycled into the reactor. Product is withdrawn from thereactor and make-up monomer is added to the recycle stream. As desiredfor temperature control of the polymerization system, any gas inert tothe catalyst composition and reactants may also be present in the gasstream.

In some embodiments, a Ziegler-Natta (ZN)catalyst is used. Suchcatalysts are based on a Group IVB transition metal compound and anorganoaluminum compound (co-catalyst). Such transition metals, include,but not limited to, Ti, Zr, and Hf Nonlimiting examples of ZN catalystsystems include TiCl₄+Et₃Al and TiCl₃+AlEt₂Cl. Such LLDPE homopolymersand/or copolymers have some long-chain branching and a density in therange of from 0.910 g/cm³ to 0.940 g/cm³.

Virgin LLDPE can be characterized by having:

-   -   i) a density in the range of from 0.910 g/cm³ to 0.940 g/cm³ or        from 0.915 g/cm³ to 0.935 g/cm³;    -   ii) a melt index (2.16 kg, 190° C.) in the range of from 1.0        g/10 min. to 100 g/10 min., from 2.0 g/10 min. to 80 g/10 min.,        or from 3.0 g/10 min. to 50 g/10 min.;    -   iii) a molecular weight distribution (M_(w)/M_(n)) greater than        15; and    -   iv) a weight average molecular weight less than or equal to        250,000 daltons, less than or equal to 200,000 daltons, less        than or equal to 150,000 daltons, or less than or equal to        100,000 daltons.

—LLDPE Recyclate Feedstock

In some embodiments, LLDPE recyclate feedstock is derived from ethylenehomopolymers, copolymers of units derived from ethylene and unitsderived from one or more of C₃-C₁₂ α-olefins, copolymers of unitsderived from ethylene and units derived from one or more of alphamono-olefins. Such C₃-C₁₂ α-olefins include, but are not limited to,substituted or unsubstituted C₃ to C₁₂ alpha olefins such as propylene,butene, pentene, hexene, heptene, octene, nonene, decene, undecene,dodecane, and isomers thereof. When present, comonomers can be presentin amounts up to 20 wt %, 15 wt %, 10 wt %, or 5 wt %. LLDPE recyclatefeedstock can be derived as a portion of post-consumer recycledpolyolefin and/or post-industrial recycled polyolefin that ispredominately comprised of LLDPE recyclate, wherein “predominately”means greater than or equal to 80 wt %, greater than or equal to 85 wt%, greater than or equal to 90 wt %, or greater than or equal to 95 wt%, based on the total weight of the LLDPE recyclate feedstock.

Such ethylene homopolymers and/or copolymers can be produced in asuspension, solution, slurry, or gas phase process, using knownequipment and reaction conditions. In some embodiments, polymerizationtemperatures range from about 0° C. to about 300° C. at atmospheric,subatmospheric, or superatmospheric pressures.

Slurry or solution polymerization systems can utilize subatmospheric orsuperatmospheric pressures and temperatures in the range of about 40° C.to about 300° C. An exemplary liquid phase polymerization system isdescribed in U.S. Pat. No. 3,324,095, the disclosure of which is fullyincorporated by reference herein. Liquid phase polymerization systemsgenerally comprise a reactor to which olefin monomer and catalystcomposition are added, and which contains a liquid reaction medium fordissolving or suspending the polyolefin. The liquid reaction medium mayconsist of the bulk liquid monomer or an inert liquid hydrocarbon thatis nonreactive under the polymerization conditions employed. Althoughsuch an inert liquid hydrocarbon need not function as a solvent for thecatalyst composition or the polymer obtained by the process, it usuallyserves as solvent for the monomers employed in the polymerization. Amongthe inert liquid hydrocarbons suitable for this purpose are isopentane,hexane, cyclohexane, heptane, benzene, toluene, and the like. Reactivecontact between the olefin monomer and the catalyst composition shouldbe maintained by constant stirring or agitation. The reaction mediumcontaining the olefin polymer product and unreacted olefin monomer iswithdrawn from the reactor continuously. The olefin polymer product isseparated, and the unreacted olefin monomer and liquid reaction mediumare recycled into the reactor.

Gas phase polymerization systems can utilize superatmospheric pressuresin the range of from 1 psig (6.9 kPag) to 1,000 psig (6.9 MPag), 50 psig(344 kPag) to 400 psig (2.8 MPag), or 100 psig (689 kPag) to 300 psig(2.1 MPag), and temperatures in the range of from 30° C. to 130° C. or65° C. to 110° C. Gas phase polymerization systems can be stirred orfluidized bed systems. In some embodiments, a gas phase, fluidized bedprocess is conducted by passing a stream containing one or more olefinmonomers continuously through a fluidized bed reactor under reactionconditions and in the presence of catalyst composition at a velocitysufficient to maintain a bed of solid particles in a suspendedcondition. A stream containing unreacted monomer is withdrawn from thereactor continuously, compressed, cooled, optionally partially or fullycondensed, and recycled into the reactor. Product is withdrawn from thereactor and make-up monomer is added to the recycle stream. As desiredfor temperature control of the polymerization system, any gas inert tothe catalyst composition and reactants may also be present in the gasstream.

In some embodiments, a Ziegler-Natta (ZN)catalyst is used. Suchcatalysts are based on a Group IVB transition metal compound and anorganoaluminum compound (co-catalyst). Such transition metals, include,but not limited to, Ti, Zr, and Hf Nonlimiting examples of ZN catalystsystems include TiCl₄+Et₃Al and TiCl₃+AlEt₂Cl. Such LLDPE homopolymersand/or copolymers have some long-chain branching and a density in therange of from 0.910 g/cm³ to 0.940 g/cm³.

LLDPE recyclate feedstock, derived from LLDPE as described above, can becharacterized by having:

-   -   i) a density in the range of from 0.910 g/cm³ to 0.940 g/cm³ or        from 0.915 g/cm³ to 0.935 g/cm³;    -   ii) a melt index (2.16 kg, 190° C.) less than or equal to less        than or equal to 5.0 g/10 min.;    -   iii) a molecular weight distribution (M_(w)/M_(n)) greater than        or equal to 5.0, greater than or equal to 7.0, greater than or        equal to 10.0, or greater than or equal to 15.0;    -   iv) a weight average molecular weight (“M_(w1)”) greater than or        equal to 85,000 daltons, greater than or equal to 120,000        daltons, greater than or equal to 180,000 daltons, or greater        than or equal to 200,000 daltons, and/or less than or equal to        500,000 daltons, less than or equal to 400,000 daltons, less        than or equal to 350,000 daltons, or less than or equal to        250,000 daltons; and    -   v) a melt elasticity (“ER”) greater than or equal to 0.5.

In some embodiments, in addition to the foregoing properties, the LLDPErecyclate feedstock can be further characterized by having one or moreof:

-   -   vi) a first VOC content;    -   vii) a first high load melt index (I₂₁, 21.6 kg, 190° C.;    -   viii) a first melt index ratio (MIR, I₂₁/I₂);    -   ix) a first long chain branching parameter (g′) in the range of        from 0.85 to 1.00, from 0.90 to 0.99, or from 0.92 to 0.98;    -   x) a first overall polydispersity ratio (PDR);    -   xi) a first complex viscosity ratio (η*_(0.1)/η*₁₀₀), wherein        η_(0.1) is the complex viscosity at 0.1 rad/sec and η*₁₀₀ is the        complex viscosity at 100 rad/sec, both at a temperature of 190°        C.; and    -   xii) a first intrinsic viscosity.

—Processed LLDPE Recyclate

A processed LLDPE recyclate is withdrawn from the discharge of thevisbreaking extruder, wherein “processed” means that the LLDPE recyclatefeedstock was subjected to visbreaking conditions or visbreakingconditions followed by devolatilization conditions. Processed LLDPErecyclate, as described above, can be characterized by having:

-   -   i) a density, wherein the ratio of the density of the processed        LLDPE recyclate to the density of the LLDPE recyclate feedstock        is greater than or equal to 1.0;    -   ii) a melt index (I₂), wherein the ratio of the melt index of        the processed LLDPE recyclate to the melt index of the LLDPE        recyclate feedstock is greater than or equal to 5.0, and/or the        processed LLDPE recyclate has a melt index (I₂) greater than or        equal to 5.0 g/10 min.;    -   iii) a molecular weight distribution, wherein the ratio of        molecular weight distribution of the processed LLDPE recyclate        to the molecular weight distribution of the LLDPE recyclate        feedstock is less than or equal to 0.8, and/or the molecular        weight distribution of the processed LLDPE recyclate is less        than or equal to 5.0;    -   iv) a weight average molecular weight (“M_(w2)”), wherein the        ratio of the weight average molecular weight of the processed        LLDPE recyclate to the weight average molecular weight of the        LLDPE recyclate feedstock is less than or equal to 0.90 or less        than or equal to 0.80; and    -   v) a melt elasticity (“ER”), wherein the ratio of the ER of the        processed LLDPE recyclate to the ER of the LLDPE recyclate        feedstock is less than or equal to 0.50, less than or equal to        0.40, or less than or equal to 0.30 and/or the second melt        elasticity is less than 0.5.

In some embodiments, in addition to the foregoing properties, theprocessed LLDPE recyclate can be further characterized by having one ormore of:

-   -   vi) a VOC content, wherein the ratio of the VOC content of the        processed LLDPE recyclate to the VOC content of the LLDPE        recyclate feedstock is less than or equal to 0.9, 0.8, 0.7, 0.6,        or 0.5, each alone or in combination with a lower limit of        greater than or equal to 0.1;    -   vii) a high load melt index (I₂₁, 21.6 kg, 190° C.), wherein the        ratio of the high load melt index of the processed LLDPE        recyclate to the high load melt index of the LLDPE recyclate        feedstock is greater than or equal to 2.0, greater than or equal        to 3.0, or greater than or equal to 4.0;    -   viii) a melt index ratio (MIR, I₂₁/I₂), wherein the MIR of the        processed LLDPE recyclate to the MIR of the LLDPE recyclate        feedstock is less than or equal to 0.90, less than or equal to        0.85, or less than or equal to 0.80;    -   ix) a long chain branching parameter (g′), wherein the ratio of        the g′ of the processed LLDPE recyclate to the g′ of the LLDPE        recyclate feedstock is less than or equal to 1.0;    -   x) a first long chain branching index (“LCBI”) greater than or        equal to 0, and the processed LLDPE recyclate has a LCBI greater        than 0;    -   xi) an overall polydispersity ratio (PDR), wherein the ratio of        the PDR of the processed LLDPE recyclate to the PDR of the LLDPE        recyclate feedstock is less than or equal to 0.90, less than or        equal to 0.80, or less than or equal to 0.70;    -   xii) a complex viscosity ratio (η*_(0.1)/η*₁₀₀), wherein the        ratio of the complex viscosity ratio of the processed LLDPE        recyclate to the complex viscosity ratio of the LLDPE recyclate        feedstock is less than or equal to 0.7, less than or equal to        0.6, or less than or equal to 0.5, and/or the complex viscosity        ratio of the processed LLDPE recyclate is less than or equal to        3.0 or less than or equal to 2.0, and η*_(0.1) is the complex        viscosity at 0.1 rad/sec and η*₁₀₀ is the complex viscosity at        100 rad/sec, both at a temperature of 190° C.; and    -   xiii) an intrinsic viscosity [η], wherein the ratio of the        intrinsic viscosity of the processed LLDPE recyclate to the        intrinsic viscosity of the LLDPE recyclate feedstock is less        than or equal to 0.90, less than or equal to 0.80, or less than        or equal to 0.70.

Melting Extruder

The polyolefin blend component and optional antioxidants and/or othercomponents are fed to a third extruder or mixer wherein the blend issubjected to melting conditions. Melting conditions are implemented inthe meting zone of the third extruder or mixer and are tailored formixtures of specific polyolefins and optionally additives. Temperature,pressure, and shear force conditions are implemented in the secondextruder or mixer sufficient to provide intimate mixing of the processedLLDPE recyclate and the virgin LLDPE and optionally additives to producea substantially homogeneous polymer blend of the processed LLDPErecyclate and the virgin LLDPE. In some embodiments, melting conditionscomprise a temperature in the melting zone in the range of from 130° C.to 250° C. or from 150° C. to 230° C.

Compounding Extruder

Processed LLDPE recyclate and a polyolefin blend component are fed to asecond extruder or mixer wherein the blend is subjected to compoundingconditions. Compounding conditions are implemented in the compoundingzone of the second extruder or mixer and are tailored for mixtures ofspecific polyolefins and optionally additives. Temperature, pressure,and shear force conditions are implemented in the second extruder ormixer sufficient to provide intimate mixing of the processed LLDPErecyclate and the virgin LLDPE and optionally additives to produce asubstantially homogeneous polymer blend of the processed LLDPE recyclateand the virgin LLDPE. In some embodiments, compounding conditionscomprise a temperature in the compounding zone of less than or equal to300° C., less than or equal to 250° C. or less than or equal to 200° C.In some embodiments, temperatures in the compounding zone can be in therange of from 125° C. to 195° C., from 130° C. to 180° C., or from 135°C. to 165° C.

Blends of Processed LLDPE Recyclate and a Polyolefin Blend Component

In some embodiments, the blend comprises from 5 wt. % to 90 wt. %, 10wt. % to 80 wt. %, 15 wt. % to 70 wt. %, 20 wt. % to 60 wt. %, or 25 wt.% to 50 wt. %, of a processed LLDPE recyclate and from 10 wt. % to 95wt. %, 20 wt. % to 90 wt. %, 30 wt. % to 85 wt. %, 40 wt. % to 80 wt. %,or 50 wt. % to 75 wt. %, of a polyolefin blend component, respectively,wherein all weight percentages are based on the combined weight of thepolymer blend. In some embodiments, the virgin LLDPE is visbroken. Suchvisbreaking of virgin LLDPE can be thermal visbreaking and/orperoxidation visbreaking. In some embodiments, such visbreakingconditions for a virgin LLDPE consist of thermal visbreaking at atemperature above the melting point of the LLDPE, greater than or equalto 300° C., or in the range of from 320° C. to 400° C., in the absenceof or substantially in the absence of oxygen.

In some embodiments, the blends of processed LLDPE recyclate and apolyolefin blend component, in combination with or independently of theblend ratios in the preceding paragraph, comprise a bimodal polymer,wherein the processed LLDPE recyclate product has a weight averagemolecular weight (“M_(w3)”), the polyolefin blend component has a weightaverage molecular weight (“M_(w4)”); and M_(w3)/M_(w4) is either lessthan or equal to 0.9, 0.8, 0.7, 0.6, or 0.5, or alternatively is greaterthan or equal to 1.1, 1.25, 1.5, 1.75, or 2.0.

CERTAIN EMBODIMENTS

In some embodiments, a method for processing linear low densitypolyethylene (LLDPE) recyclate comprises providing a LLDPE recyclatefeedstock, adding the LLDPE recyclate to a first extruder to produce afirst LLDPE recyclate melt, and subjecting the first LLDPE recyclatemelt to visbreaking conditions to produce a second LLDPE recyclate melt.The LLDPE recyclate feedstock has: a first density in the range of from0.910 g/cm³ to 0.940 g/cm³; a first melt index (2.16 kg, 190° C.) lessthan or equal to 5.0 g/10 min; a first molecular weight distribution(M_(w)/M_(n)) greater than or equal to 5.0, greater than or equal to7.0, greater than or equal to 10.0, or greater than or equal to 15.0; afirst weight average molecular weight (“M_(w1)”) greater than or equalto 85,000 daltons, greater than or equal to 120,000 daltons, greaterthan or equal to 180,000 daltons, or greater than or equal to 200,000daltons, and/or less than or equal to 500,000 daltons, less than orequal to 400,000 daltons, less than or equal to 350,000 daltons, or lessthan or equal to 250,000 daltons; and a first melt elasticity (“ER”)greater than or equal to 0.5.

The second LLDPE recyclate melt has: a second density, wherein the ratioof the second density to the first density is greater than or equal to1.0; a second melt index, wherein the ratio of the second melt index tothe first melt index is greater than or equal to 5.0, and/or theprocessed LLDPE recyclate has a melt index (I₂) greater than or equal to5.0 g/10 min.; a second molecular weight distribution, wherein the ratioof second molecular weight distribution to the first molecular weightdistribution is less than or equal to 0.8, and/or the molecular weightdistribution of the processed LLDPE recyclate is less than or equal to5.0; a second weight average molecular weight (“M_(w2)”), whereinM_(w2)/M_(w1) i is less than or equal to 0.90 or less than or equal to0.80; and a second melt elasticity, wherein the ratio of the second meltelasticity to the first melt elasticity is less than or equal to 0.50,less than or equal to 0.40, or less than or equal to 0.30 and/or thesecond melt elasticity is less than 0.50.

In further embodiments, the method is additionally characterized by oneor more of the following:

-   -   a) the LLDPE recyclate feedstock comprises post-consumer        recycled waste, post-industrial recycled waste, or a combination        thereof;    -   b) the visbreaking conditions consist of thermal visbreaking,        which in some instances is performed at a temperature greater        than or equal to 300° C., or at a temperature in the range of        from 320° C. to 400° C.;    -   c) the first LLDPE recyclate melt is further subjected to        devolatilization conditions to produce the second LLDPE        recyclate melt, wherein the LLDPE recyclate feedstock has a        first volatile organic compound content, the first LLDPE        recyclate melt has a second volatile organic compound content,        and the ratio of the second volatile organic compound content to        the first volatile organic compound content is less than or        equal to 0.9, and in some instances, the devolatilization        conditions further comprise:        -   i) injection and withdrawal of a scavenging gas, and in some            instances the scavenging gas comprises nitrogen,            carbon-dioxide, water, or combinations thereof,        -   ii) vent conditions, vacuum conditions, or a combination            thereof,    -   d) the second LLDPE recyclate melt is passed through a melt        filter;    -   e) an antioxidant agent is added to the first extruder; and    -   f) the LLDPE recyclate feedstock has a first high load melt        index (21.6 kg, 190° C.), the second LLDPE recyclate melt has a        second high load melt index, and the ratio of the second high        load melt index to the first high load melt index is greater        than or equal to 2.0, greater than or equal to 3.0, or greater        than or equal to 4.0;    -   g) the LLDPE recyclate feedstock has a first melt index ratio        (I₂₁/I₂), the second LLDPE recyclate melt has a second melt        index ratio, and the ratio of the second melt index ratio to the        first melt index ratio is less than or equal to 0.90, less than        or equal to 0.85, or less than or equal to 0.80;    -   h) the LLDPE recyclate feedstock has a first long chain        branching parameter (g′) in the range of from 0.85 to 1.00, from        0.90 to 0.99, or from 0.92 to 0.98, a second LLDPE recyclate        and/or the ratio of the second g′ to the first g′ is less than        or equal to 1.0;    -   i) the LLDPE recyclate feedstock has a first long chain        branching index (“LCBI”) greater than or equal to 0, and the        processed LLDPE recyclate has a LCBI greater than 0;    -   j) the LLDPE recyclate feedstock has an overall polydispersity        measure (“PDR”), the second LLDPE recyclate melt has a second        PDR, and the ratio of the second PDR to the first PDR is less        than or equal to 0.90, less than or equal to 0.80, or less than        or equal to 0.70;    -   k) the LLDPE recyclate feedstock has a first complex viscosity        ratio (η*_(0.1)/η*₁₀₀), wherein the ratio of the complex        viscosity ratio of the processed LLDPE recyclate to the complex        viscosity ratio of the LLDPE recyclate feedstock is less than or        equal to 0.7, less than or equal to 0.6, or less than or equal        to 0.5, and/or the complex viscosity ratio of the processed        LLDPE recyclate is less than or equal to 3.0 or less than or        equal to 2.0; and    -   l) the LLDPE recyclate feedstock has a first intrinsic        viscosity, the second LLDPE recyclate melt has an intrinsic        viscosity, and the ratio of the second intrinsic viscosity to        the first intrinsic viscosity is less than or equal to 0.90,        less than or equal to 0.80, or less than or equal to 0.70

In some embodiments, the foregoing method further comprises forming aLLDPE recyclate product by withdrawal of the second LLDPE recyclate meltfrom the first extruder for further processing or pelletizing of thesecond LLDPE recyclate melt.

In further embodiments of the foregoing method, the LLDPE recyclateproduct and a first polyolefin blend component are added to a secondextruder, and compounding conditions are effected in the second extruderto form a polyolefin product comprising the melt-blended mixture of theprocessed LLDPE recyclate product and the first polyolefin blendcomponent. In some embodiments, such compounding condition include atemperature less than or equal to 300° C. In some embodiments, the firstpolyolefin blend component comprises a virgin polyolefin, a polyolefinrecyclate feedstock, a processed polyolefin recyclate, or a combinationthereof. In yet further embodiments: the virgin polyolefin comprises avirgin LDPE, a virgin LLDPE, a virgin HDPE, a virgin MDPE, a virginpolypropylene, or a combination thereof; the polyolefin recyclatefeedstock comprises a LDPE recyclate feedstock, a LLDPE recyclatefeedstock, a HDPE recyclate feedstock, a MDPE recyclate feedstock, apolypropylene recyclate feedstock, or a combination thereof; and theprocessed polyolefin recyclate comprises a processed LDPE recyclate, asecond processed LLDPE recyclate, a processed HDPE recyclate, aprocessed MDPE recyclate, a processed polypropylene recyclate, or acombination thereof. In some embodiments, the first polyolefin blendcomponent comprises a virgin LLDPE, a LLDPE recyclate feedstock, aprocessed LLDPE recyclate, or a combination thereof.

In further embodiments of the foregoing method, the LLDPE recyclateproduct: is added in an amount in the range of from 5 wt. % to 90 wt. %,or from 20 wt. % to 60 wt. %, based on the combined weight of the LLDPErecyclate product and the first polyolefin blend component; and/or theLLDPE recyclate product has third weight average molecular weight(“M_(w3)”), the first polyolefin blend component has a fourth weightaverage molecular weight (“M_(w4)”), and the M_(w3)/M_(w3) is eitherless than or equal to 0.8 or greater than or equal to 1.25.

In further embodiments of the foregoing method, the first polyolefinblend component is a first virgin LLDPE comprising a polymer productprepared in a first polymerization apparatus, wherein in some instances,the polymer product was subjected to a visbreaking process afterpolymerization, and in some embodiments, the visbreaking processcomprises thermal visbreaking, peroxide visbreaking, or a combinationthereof.

In further embodiments of the foregoing method, the first polyolefinblend component comprises a polyolefin powder prepared in a firstpolymerization apparatus.

In further embodiments of the foregoing method, an antioxidant agent isadded to the second extruder.

In further embodiments of the foregoing method, the method furthercomprises: adding a second polyolefin blend component to a thirdextruder; effecting melt conditions in the third extruder to produce asecond polyolefin blend component melt; and withdrawing the secondpolyolefin blend component melt as the first polyolefin blend component.

In further embodiments of the foregoing method, the second polyolefinblend component comprises a virgin LLDPE, a LLDPE recyclate feedstock, aprocessed LLDPE recyclate, or a combination thereof.

In further embodiments of the foregoing method, the second polyolefinblend component is subjected to a visbreaking process afterpolymerization, wherein in some instances, the visbreaking processconsists of thermal visbreaking.

In further embodiments of the foregoing method, the second polyolefinblend component comprises polyethylene powder prepared in a secondpolymerization apparatus and/or polyethylene pellets.

In further embodiments of the foregoing method, the first and/or secondpolymerization apparatus each comprise two more polymerization reactorsand/or two or more polymerization zones within a polymerization reactor.

In further embodiments of the foregoing method, the first and/or secondpolymerization apparatuses each comprise two or more gas phasefluidized-bed reactors in series, two or more slurry phase reactors inseries, or a gas phase fluidized-bed reactor in series with a multizonecirculation reactor.

In further embodiments of the foregoing method, an antioxidant agent isadded to the third extruder.

In some embodiments, a composition comprise a polymer blend of a firstpolymer and a second polymer. The first polymer is a first processedLLDPE recyclate and is present in an amount in the range of from 5 wt. %to 90 wt. %. The second polymer is a virgin polyolefin, a polyolefinrecyclate feedstock, a processed polyolefin recyclate, or a combinationthereof, and is present in an amount in the range of from 10 wt. % to 95wt. %. All weight percentages are based on the combined weight of thefirst and second polymers.

In further embodiments of the foregoing composition: the virginpolyolefin comprises a virgin LDPE, a virgin LLDPE, a virgin HDPE, avirgin MDPE, a virgin polypropylene, or a combination thereof; thepolyolefin recyclate feedstock comprises a LDPE recyclate feedstock, aLLDPE recyclate feedstock, a HDPE recyclate feedstock, a MDPE recyclatefeedstock, a polypropylene recyclate feedstock, or a combinationthereof; and the processed polyolefin recyclate comprises a processedLDPE recyclate, a second processed LLDPE recyclate, a processed HDPErecyclate, a processed MDPE recyclate, a processed polypropylenerecyclate, or a combination thereof.

In further embodiments of the foregoing composition, processed meanssubjected to thermal visbreaking or subjected to thermal visbreaking anddevolatilization. In some embodiments, a blend comprises a visbrokenLLDPE, having a first I₂ and a virgin LLDPE, a LLDPE recyclatefeedstock, a processed LLDPE recyclate, or a combination thereof, havinga second I₂, wherein:

${\log( ( I_{2} )_{blend} )} = {\sum\limits_{i = 1}^{n}( {w_{i} \times \log( ( I_{2} )_{i} )} )}$

-   -   (I₂)_(blend) is the target melt index of the final blend        product;    -   n is the number of components in the blend; and    -   i is the i-th component of an n-component blend.

The following examples illustrate the invention; however, those skilledin the art will recognize numerous variations within the spirit of theinvention and scope of the claims. To facilitate a better understandingof the present invention, the following examples of preferredembodiments are given. In no way should the following examples be readto limit, or to define, the scope of the invention.

EXAMPLES

The following examples are included to demonstrate preferred embodimentsof the invention. It should be appreciated by those of skill in the artthat the techniques disclosed in the examples which follow representtechniques discovered by the inventor to function well in the practiceof the invention, and thus can be considered to constitute preferredmodes for its practice. However, those of skill in the art should, inlight of the present disclosure, appreciate that many changes can bemade in the specific embodiments which are disclosed and still obtain alike or similar result without departing from the spirit and scope ofthe invention.

The following examples use commercial LLDPE compositions having a lowmelt index as proxies for LLDPE recyclate feedstocks. After processing,as described herein, the visbroken low melt index LLDPEs, either aloneor in blends with other components, are compared to higher melt indexvirgin LLDPEs.

Test Methods

Densities are determined in accordance with ASTM D-4703 and ASTMD-1505/ISO-1183.

High load melt index (“I₂₁”) was determined by ASTM D-1238-F (190°C./21.6 kg).

Shear rheological measurements are performed in accord with ASTM4440-95a, which characterize dynamic viscoelastic properties (storagemodulus, G′, loss modulus, G″ and complex viscosity, η*, as a functionof oscillation frequency, ω). A rotational rheometer (TA Instruments) isused for the rheological measurements. A 25 mm parallel-plate fixturewas utilized. Samples were compression molded in disks (˜29 mm diameterand ˜1.3 mm thickness) using a hot press at 190° C. An oscillatoryfrequency sweep experiment (from 398.1 rad/s to 0.0251 rad/s) wasapplied at 190° C. The applied strain amplitude is ˜10% and theoperating gap is set at 1 mm. Nitrogen flow was applied in the samplechamber to minimize thermal oxidation during the measurement.

Melt elasticity (“ER”) is determined as discussed in R. Shroff and H.Mavridis, “New Measures of Polydispersity from Rheological Data onPolymer Melts,” J. Applied Polymer Science 57 (1995) 1605. See also U.S.Pat. Nos. 7,238,754, 6,171,993 and 5,534,472 (col. 10, lines 20-30), theteachings of which are incorporated herein by reference. Thus, storagemodulus (G′) and loss modulus (G″) are measured. The nine lowestfrequency points are used (five points per frequency decade) and alinear equation is fitted by least-squares regression to log G′ versuslog G″. ER is then calculated from:

ER=(1.781×10⁻³)×G′

at a value of G″=5,000 dyn/cm². The same procedure and equation for theER calculation was used for both linear and long-chain-branchedpolyolefins.

PDR or “Overall Polydispersity Measure” is determined as discussed in R.Shroff and H. Mavridis, “New Measures of Polydispersity from RheologicalData on Polymer Melts.” J. Applied Polymer Science 57 (1995) 1605,equation 27 on page 1619, with G*_(ref,1)=1.95*10⁴ dyn/cm² andlog₁₀(G*_(ref,3)/G*_(ref,1))=2 The same procedure and equation for thePDR calculation was used for both linear and long-chain-branchedpolyolefins.

The ratio η*_(0.1)/η*₁₀₀ of complex viscosities, 0.1, at a frequency of0.1 rad/sec and η*₁₀₀, at a frequency of 100 rad/sec, is used as anadditional measure of shear sensitivity and thus rheological breadth, orpolydispersity, of the polymer melt.

Melt index (“I₂”) was determined by ASTM D-1238-E (190° C./2.16 kg).

Molecular weight distribution (“MWD”) as well as the molecular weightaverages (number-average molecular weight, M_(n), weight-averagemolecular weight, M_(w), and z-average molecular weight, M_(z)) aredetermined using a high temperature Polymer Char gel permeationchromatography (“GPC”), also referred to as size exclusionchromatography (“SEC”), equipped with a filter-based infrared detector,IR5, a four-capillary differential bridge viscometer, and a Wyatt18-angle light scattering detector. M_(n), M_(w), M_(z), MWD, and shortchain branching (SCB) profiles are reported using the IR detector,whereas long chain branch parameter, g′, is determined using thecombination of viscometer and IR detector at 145° C. Three Agilent PLgelOlexis GPC columns are used at 145° C. for the polymer fractionationbased on the hydrodynamic size in 1,2,4-trichlorobenzene (TCB) with 300ppm antioxidant butylated hydroxytoluene (BHT) as the mobile phase. 16mg polymer is weighted in a 10 mL vial and sealed for the GPCmeasurement. The dissolution process is obtained automatically (in 8 mlTCB) at 160° C. for a period of 1 hour with continuous shaking in anAgilent autosampler. 20 μL Heptane was also injected in the vial duringthe dissolution process as the flow marker. After the dissolutionprocess, 200 μL solution was injected in the GPC column. The GPC columnsare calibrated based on twelve monodispersed polystyrene (PS) standards(provided by PSS) ranging from 578 g/mole to 3,510,000 g/mole. Thecomonomer compositions (or SCB profiles) are reported based on differentcalibration profiles obtained using a series of relatively narrowpolyethylene (polyethylene with 1-hexene and 1-octene comonomer wereprovided by Polymer Char, and polyethylene with 1-butene weresynthesized internally) with known values of CH₃/1000 total carbon,determined by an established solution NMR technique. GPC one softwarewas used to analyze the data. The long chain branch parameter, g′, isdetermined by the equation:

g′=[η]/[η]_(lin)

where, [η] is the average intrinsic viscosity of the polymer that isderived by summation of the slices over the GPC profiles as follows:

$\lbrack\eta\rbrack = \frac{\Sigma{c_{i}\lbrack\eta\rbrack}_{i}}{\Sigma c_{i}}$

where c_(i) is the concentration of a particular slice obtained from IRdetector, and [η]_(i) is the intrinsic viscosity of the slice measuredfrom the viscometer detector. [η]_(lin) is obtained from the IR detectorusing Mark-Houwink equation ([η]_(lin)=ΣKM_(i) ^(α)) for a linear highdensity polyethylene, where M_(i) is the viscosity-average molecularweight for a reference linear polyethylene, K and α are Mark-Houwinkconstants for a linear polymer, which are K=0.000374, α=0.7265 for alinear polyethylene and K=0.00041, α=0.6570 for a linear polypropylene.

Volatile Organic Compounds (“VOC”) is measured by pyrolysis-gaschromatography/mass spectrometry (“P-GC/MS”) in parts per billion (ppb),parts per million (ppm), or and micrograms per cubic meter (μg/m³).

Zero-shear viscosity, η₀, is determined using the Sabia equation fit ofdynamic complex viscosity versus radian frequency, as described in ofShroff & Mavridis, (1999) “A Long Chain Branching Index for EssentiallyLinear Polyethylenes”, Macromolecules, 32, 8454-8464 (with focus onAppendix B), the disclosure of which is fully incorporated by referenceherein in its entirety.

LCBI is determined using equation 13:

$\begin{matrix}{{LCBI} = {{\frac{\eta_{0}^{0.179}}{\lbrack\eta\rbrack}\frac{1}{4.8}} - 1}} & (13)\end{matrix}$

Equation 13 and its application are described in of Shroff & Mavridis,(1999) “A Long Chain Branching Index for Essentially LinearPolyethylenes”, Macromolecules, 32, 8454-8464, the disclosure of whichis fully incorporated by reference herein in its entirety.

Long Chain Branching frequency, characterized by the ratio of Long ChainBranches per million carbon atoms, or LCB/10⁶ C, was determined by themethod of Janzen & Colby (J. Janzen and R. H. Colby, “Diagnosinglong-chain branching in polyethylenes”, Journal of Molecular Structure,Vol 485-486, 10 Aug. 1999, Pages 569-583), using eqs.(2-3) and theconstants of Table 2 in the above reference. Specifically, thezero-shear viscosity at 190° C., η*₀, is determined by extrapolation ofthe complex viscosity data via the Sabia equation, as describedseparately. The weight-average-molecular weight, M_(w), is determinedvia GPC. With these two parameters and the methodology of Janzen &Colby, the Long Chain Branching frequency, LCB/10⁶ C, can be determinednumerically such that all 3 parameters (η₀, M_(w) and LCB/10⁶ C) satisfyeqs. (2-3) in the above reference. The Janzen & Colby methodologypredicts that the ratio, η₀/η_(0,linear) of the zero-shear viscosity ofthe material, over the zero-shear viscosity of a perfectly linearpolymer (LCB/10⁶ C=0) of the same average molecular weight, exhibits amaximum at a certain value of LCB/10⁶ C and therefore for every value ofη₀/η_(0,linear), there exist two levels, or values, of LCB/10⁶ C thatsuch ratio is possible. For the purposes of the present calculations,the lowermost value of LCB/10⁶ C was always selected at the given ratioof η₀/η_(0,linear).

Raw Materials

Raw materials used herein are shown in Table 1, below.

TABLE 1 MFR Polymer (8/10 Density Composition** Use in Examples Labelmin)* (g/cc) LyondellBaselI ™ Proxy for LLDPE P1 2.1 0.921 HF 1820recyclate feedstock *190° C./2.16 kg **All materials available fromLyondellBasell Industries NV

Examples 1-3

Examples 1-3 in TABLE 2 show the results of visbreaking a LLDPE resin.P1 is believed to fairly represent an LLDPE recyclate feedstock. Priorto processing, P1 (LLDPE recyclate feedstock proxy) has a nominaldensity of 0.921 g/cm³ and melt index I₂ of 2.1 g/10 min. Example 1results in TABLE 2 show a number of other properties of P1.

Examples 2 and 3 were prepared by visbreaking portions of P1.Visbreaking was performed by feeding P1 into a Werner and PfleidererZSK40 twin screw extruder at a feed rate of 50 pounds per hour, a screwspeed of 600 rpm and with a target temperature profile of200/250/325/325/325/325/325/325/325° C. (from feed inlet to die). Theextrudate was comminuted to pellets. In Examples 2 and 3 different screwdesigns were used resulting in increased energy input into the polymerin the extruder in Example 3 versus Example 2. The visbroken P1 ofExample 2 using the first extruder screw design is labeled P1-vb1, andthe visbroken P1 of Example 3 using the second extruder screw design islabeled P1-vb2, in TABLE 2.

Example 2 shows that melt index I₂ of P1 is increased by visbreaking bya factor of 6.4, while density increased only nominally. Example 3 showsthat melt index I₂ of P1 is increased by visbreaking by a factor of 7.2.Differences in melt index I₂ in Examples 2 and 3 are attributed tospecific energy (“SPE”) input to the polymers of 0.498 kW·hr/kg and0.540 kW·hr/kg, respectively.

Examples shows that high load melt index I₂₁ of P1 is increased byvisbreaking by a factor of 4.9, and producing a reduction of melt indexratio (I₂₁/I₂) from 29 to 22. Melt elasticity (“ER”) is reduced by abouthalf in both Examples 2 and 3. Overall polydispersity measure (“PDR”) isreduced by about one thirds for both Examples 2 and 3.

As compared to P1, complex viscosities η₀, η*_(0.1) and η*₁₀₀ are allreduced by orders of magnitude, and complex viscosity ratioη*_(0.1)/η*₁₀₀ is reduced by about half in Examples 2 and 3. Intrinsicviscosity [η] is reduced by about a third in Examples 2 and 3.

As compared to P1, number average molecular weight (M_(n)) is reduced by19% and 27%, weight average molecular weight (M_(w)) is reduced by 42%and 43%, and Z-average molecular weight (M_(z)) is reduced by 53% and54%, in Examples 2 and 3, respectively. Molecular weight distribution(M_(w)/M_(n)) is reduced by 28% and 21%, and molecular weight ratio(M_(z)/M_(w)) is reduced by 19% and 20%, in Examples 2 and 3,respectively.

TABLE 2 Example Parameter Units 1 2 3 Polymer Label — P1 P1-vb1 P1-vb2I₂ g/10 min 2.1 13.3 15.0 I₂-vb/I₂-original — — 6.4 7.2 Density g/cc0.921 0.924 0.924 I₂₁ g/10 min 60.1 293 — I₂₁₋vb/I₂₁-original — — 4.9 —MIR (I₂₁/I₂) — 29 22 — ER — 0.63 0.31 0.29 ER-vb/ER -original % — 0.490.46 PDR — 3.5 2.3 2.2 PDR-vb/PDR-original % — 0.64 0.62 η₀ poise 4.67 ×10⁴ 6.54 × 10³ 5.48 × 10³ η*_(0.1) poise 4.19 × 10⁴ 6.46 × 10³ 5.46 ×10³ η*₁₀₀ poise 1.10 × 10⁴ 3.73 × 10³ 3.34 × 10³ n*_(0.1)/n*₁₀₀ — 3.81.7 1.6 Vinyl/1000 C (NMR) — — — — M_(n) daltons 20,830 17,021 15,216M_(w) daltons 110,400 64,000 63,300 M_(z) daltons 338,400 158,200155,000 MWD (M_(w)/M_(n)) — 5.3 3.8 4.2 M_(z)/M_(w) — 3.1 2.5 2.4M_(w)-vb/M_(w)-original — — 0.58 0.57 M_(z)-vb/M_(z)-original — — 0.470.46 (M_(z)/M_(w))-vb/(M_(z)/M_(w))-orig. — — 0.81 0.80 IntrinsicViscosity [η] dl/g 1.44 0.97 0.93 g′ (long chain branching — 0.95 0.920.89 parameter) LCBI — −0.01 0.04 0.05 LCB/10⁶ C — 11 29 26 SPE hp ·hr/lb — 0.304 0.329 kW · hr/kg — 0.498 0.540 vh = vichrolan

Dynamic oscillatory data generated based on analysis of samples of P1,P1-vb1, and P1-vb2 are shown in TABLE 3 below. The data in TABLE 3 showthat complex viscosity decreases as frequency increases for all of P1,P1-vb1, and P1-vb2. TABLE 3 further shows that visbreaking P1 results ina lower complex viscosity (η*) for P1-vb1 and P1-vb2 for all testedvalues of frequency. Additionally, the difference in complex viscositybetween P1 and both P1-vb1 and P1-vb2 decreases as frequency increase.Applicant believes this to show, without wishing to be bound by anyparticular theory, that visbreaking has a bigger impact, that is morechain scission, on higher molecular weight chains in LLDPE and furtherindicates a narrower MWD (M_(w)/M₁₁) for P1-vb1 as compared to P1. FIG.4 a comparison of curves generated for Examples 1-3 from the data inTABLE 3. The overlaid graphs show the log of complex viscosity (η*) inpoise as a function of the log of the oscillatory frequency in radiansper second.

TABLE 3 Example 1 Example 2 Example 3 Oscillation (P1) (P2) (P3) Freq.Log η* Log η* Log η* log (rad/sec) (freq.) (poise) (η*) (poise) η*)(poise) (η*) 0.0251 −1.60 43,500 4.64 — — — — 0.0398 −1.40 43,000 4.63 —— — — 0.0631 −1.20 42,500 4.63 — — — — 0.100 −1.00 41,900 4.62 — — — —0.158 −0.80 41,100 4.61 — — — — 0.251 −0.60 40,200 4.60 6,290 3.80 5,2903.72 0.398 −0.40 39,000 4.59 6,270 3.80 5,260 3.72 0.631 −0.20 37,6004.58 6,230 3.79 5,230 3.72 1.00 0.00 35,900 4.56 6,180 3.79 5,190 3.721.58 0.20 34,000 4.53 6,110 3.79 5,150 3.71 2.51 0.40 31,800 4.50 6,0103.78 5,080 3.71 3.98 0.60 29,600 4.47 5,890 3.77 4,990 3.70 6.31 0.8027,000 4.43 5,710 3.76 4,860 3.69 10.0 1.00 24,200 4.38 5,510 3.74 4,7203.67 15.8 1.20 21,400 4.33 5,250 3.72 4,530 3.66 25.1 1.40 18,500 4.274,930 3.69 4,290 3.63 39.8 1.60 15,800 4.20 4,580 3.66 4,020 3.60 63.11.80 13,300 4.12 4,140 3.62 3,690 3.57 100 2.00 11,000 4.04 3,730 3.573,340 3.52 158 2.20 8,930 3.95 3,340 3.52 3,000 3.48 251 2.40 7,150 3.852,990 3.48 2,680 3.43 398 2.60 5,580 3.75 2,580 3.41 2,310 3.36

FIG. 5 a comparison of molecular weight curves generated for Examples1-3. The overlaid graphs demonstrate both the reduction in molecularweight and narrowing of molecular weight distribution accomplishedthrough visbreaking.

For the sake of brevity, only certain ranges are explicitly disclosedherein. However, in addition to recited ranges, any lower limit may becombined with any upper limit to recite a range not explicitly recited,as well as, ranges from any lower limit may be combined with any otherlower limit to recite a range not explicitly recited, in the same way,ranges from any upper limit may be combined with any other upper limitto recite a range not explicitly recited. Additionally, within a rangeincludes every point or individual value between its end points eventhough not explicitly recited. Thus, every point or individual value mayserve as its own lower or upper limit combined with any other point orindividual value or any other lower or upper limit, to recite a rangenot explicitly recited.

Although the present invention and its advantages have been described indetail, it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of the invention as defined by the appended claims. Moreover, thescope of the present application is not intended to be limited to theparticular embodiments of the processes, machines, film structures,composition of layers, means, methods, and/or steps described in thespecification. As one of the ordinary skill in the art will readilyappreciate from the disclosure of the present invention, processes,machines, film structures, composition of layers, means, methods, and/orsteps, presently existing or later to be developed that performsubstantially the same function or achieve substantially the same resultas the corresponding embodiments described herein, may be utilizedaccording to the present invention. Accordingly, the appended claims areintended to include within their scope such processes, machines, filmstructures, composition of layers, means, methods, and/or steps.

What is claimed is:
 1. A method for processing linear low densitypolyethylene (LLDPE) recyclate comprising: a. providing a LLDPErecyclate feedstock having: i) a first density in the range of from0.910 g/cm³ to 0.940 g/cm³; ii) a first melt index (I₂) less than orequal to 5.0 g/10 min; iii) a first molecular weight distribution(M_(w)/M₁) greater than 5.0; iv) a first weight average molecular weight(“M_(w1)”) greater than or equal to 85,000 daltons; and v) a first meltelasticity (“ER”) greater than or equal to 0.5; b. adding the LLDPErecyclate to a first extruder to produce a first LLDPE recyclate melt;and c. subjecting the first LLDPE recyclate melt to visbreakingconditions to produce a second LLDPE recyclate melt having: i) a seconddensity, wherein the ratio of the second density to the first density isgreater than or equal to 1.0; ii) a second melt index, wherein the ratioof the second melt index to the first melt index is greater than orequal to 5.0; iii) a second molecular weight distribution, wherein theratio of second molecular weight distribution to the first molecularweight distribution is less than or equal to 0.8; iv) a second weightaverage molecular weight (“M_(w2)”), wherein M_(w2)/M_(w1) is less thanor equal to 0.90; and v) a second melt elasticity, wherein the ratio ofthe second melt elasticity to the first melt elasticity is less than orequal to 0.50 and/or the second melt elasticity is less than 0.5.
 2. Themethod of claim 1, wherein the LLDPE recyclate feedstock comprisespost-consumer recycled waste, post-industrial recycled waste, or acombination thereof.
 3. The method of claim 1, wherein the visbreakingconditions consist of thermal visbreaking.
 4. The method of claim 3,wherein thermal visbreaking is performed at a temperature greater thanor equal to 300° C.
 5. The method of claim 1, further comprise furthersubjecting the first LLDPE recyclate melt to devolatilization conditionsto produce the second LLDPE recyclate melt wherein: the LLDPE recyclatefeedstock has a first volatile organic compound content; the first LLDPErecyclate melt has a second volatile organic compound content; and theratio of the second volatile organic compound content to the firstvolatile organic compound content is less than or equal to 0.9.
 6. Themethod of claim 5, wherein devolatilization conditions compriseinjection and withdrawal of a scavenging gas.
 7. The method of claim 1,wherein the method is characterized by one or more of the following: i)the LLDPE recyclate feedstock has a first high load melt index (I₂₁),the second LLDPE recyclate melt has a second high load melt index, andthe ratio of the second high load melt index to the first high load meltindex is greater than or equal to 2.0; ii) the LLDPE recyclate feedstockhas a first melt index ratio (I₂₁/I₂), the second LLDPE recyclate melthas a second melt index ratio, and the ratio of the second melt indexratio to the first melt index ratio is less than or equal to 0.90; iii)the LLDPE recyclate feedstock has a first long chain branching parameter(g′) in the range from 0.85 to 1.00, the second LLDPE recyclate melt hasa second g′, and the ratio of the second g′ to the first g′ is less thanor equal to 1.0; iv) the LLDPE recyclate feedstock has a first longchain branching index (“LCBI”) less than or equal to 0, and the secondLLDPE recyclate melt has a second LCBI”) greater than 0; v) the LLDPErecyclate feedstock has an overall polydispersity measure (“PDR”), thesecond LLDPE recyclate melt has a second PDR, and the ratio of thesecond PDR to the first PDR is less than or equal to 0.90; vi) the LLDPErecyclate feedstock has a first complex viscosity ratio, the secondLLDPE recyclate melt has a second complex viscosity ratio, and the ratioof the second complex viscosity ratio to the first complex viscosityratio is less than or equal to 0.70, and/or the second complex viscosityratio is less than or equal to 3.0; and vii) the LLDPE recyclatefeedstock has a first intrinsic viscosity, the second LLDPE recyclatemelt has a second intrinsic viscosity, and the ratio of the secondintrinsic viscosity to the first intrinsic viscosity is less than orequal to 0.90.
 8. The method of claim 1, wherein a LLDPE recyclateproduct is formed by withdrawal of the second LLDPE recyclate melt fromthe first extruder for further processing or pelletizing of the secondLLDPE recyclate melt.
 9. The method of claim 8, further comprising:adding the LLDPE recyclate product and a first polyolefin blendcomponent to a second extruder; and effecting compounding conditions inthe second extruder to form a polyolefin product comprising themelt-blended mixture of the processed LLDPE recyclate product and thefirst polyolefin blend component.
 10. The method of claim 9, wherein thefirst polyolefin blend component comprises a virgin polyolefin, apolyolefin recyclate feedstock, a processed polyolefin recyclate, or acombination thereof.
 11. The composition of claim 10, wherein: a. thevirgin polyolefin comprises a virgin LDPE, a virgin LLDPE, a virginHDPE, a virgin MDPE, a virgin polypropylene, or a combination thereof,b. the polyolefin recyclate feedstock comprises a LDPE recyclatefeedstock, a LLDPE recyclate feedstock, a HDPE recyclate feedstock, aMDPE recyclate feedstock, a polypropylene recyclate feedstock, or acombination thereof, and c. the processed polyolefin recyclate comprisesa processed LDPE recyclate, a second processed LLDPE recyclate, aprocessed HDPE recyclate, a processed MDPE recyclate, a processedpolypropylene recyclate, or a combination thereof.
 12. The method ofclaim 11, wherein the first polyolefin blend component comprises avirgin LLDPE, a LLDPE recyclate feedstock, a processed LLDPE recyclate,or a combination thereof.
 13. The method of claim 9, wherein the LLDPErecyclate product is added in an amount in the range of from 5 wt. % to90 wt. % based on the combined weight of the LLDPE recyclate product andthe first polyolefin blend component.
 14. The method of claim 9, whereinthe compounding conditions include a temperature less than or equal to300° C.
 15. The method of claim 9, further comprising: adding a secondpolyolefin blend component to a third extruder; effecting meltconditions in the third extruder to produce a second polyolefin blendcomponent melt; and withdrawing the second polyolefin blend componentmelt as the first polyolefin blend component.
 16. The method of claim15, wherein the second blend component comprises a virgin LLDPE, a LLDPErecyclate feedstock, a processed LLDPE recyclate, or a combinationthereof.
 17. A composition comprising a polymer blend of: a. a firstpolymer, wherein the first polymer: i) is a first processed LLDPErecyclate; and ii) is present in an amount in the range of from 5 wt. %to 90 wt. %; and b. a second polymer, wherein the second polymer: i) isa virgin polyolefin, a polyolefin recyclate feedstock, a processedpolyolefin recyclate, or a combination thereof; and ii) is present in anamount in the range of from 10 wt. % to 95 wt. %; wherein all weightpercentages are based on the combined weight of the first and secondpolymers.
 18. The composition of claim 17, wherein: a. the virginpolyolefin comprises a virgin LDPE, a virgin LLDPE, a virgin HDPE, avirgin MDPE, a virgin polypropylene, or a combination thereof; b. thepolyolefin recyclate feedstock comprises a LDPE recyclate feedstock, aLLDPE recyclate feedstock, a HDPE recyclate feedstock, a MDPE recyclatefeedstock, a polypropylene recyclate feedstock, or a combinationthereof; and c. the processed polyolefin recyclate comprises a processedLDPE recyclate, a second processed LLDPE recyclate, a processed HDPErecyclate, a processed MDPE recyclate, a processed polypropylenerecyclate, or a combination thereof.
 19. The composition of claim 17,wherein processed means subjected to thermal visbreaking and optionallysubjected to devolatilization.
 20. A blend comprising: a visbrokenLLDPE, having a first I₂; and a virgin LLDPE, a LLDPE recyclatefeedstock, a processed LLDPE recyclate, or a combination thereof, havinga second I₂; wherein:${\log( ( I_{2} )_{blend} )} = {\sum\limits_{i = 1}^{n}( {w_{i} \times \log( ( I_{2} )_{i} )} )}$(I₂)_(blend) is the target melt index of the final blend product; n isthe number of components in the blend; and i is the i-th component of ann-component blend.